Again, my most egregious apologies for this post which is quite long. And I realize I use run-on sentences sometimes; I had an English professor warn me about that...
A list is not that different in that regard.
Firstly, I am going to take up for Rickyp's POV in this respect. [Yes, gentlemen, you may well pick yourselves off of the floor.

Now: I do not entirely understand how this ties in with "safe seats" if someone will explain that to me. Personally, I would think ricky's 250 party-list congressmen would not be very "safe" at all, since their party's performance would affect the number of them (how many out of the 250 at-large congressmen, I mean) would belong to a particular party. Now of course, if the United States suddenly used Ricky's constitution (let's call it the Constitution of 2014, to replace the Constitution of 1787). While I do not [yet] live in a parliamentary democracy, I know for a fact that Germany is not the only western or "westernized" country whose parliament is half single member FPTP (or single-member but "preferential", such as Australia's House of Representatives) and half at-large, party-list members. (If I am not mistaken, all 120 members of the Israeli Knesset [Parliament] are elected as such, NONE of them are from districts/ridings/constituencies/etc!) Now of course, Israel is a very small country, population 7,821,850,* far smaller in size and population than Germany (or the United Kingdom, Canada, the United States, etc.) so maybe it is logical that the entire country is a whole district of the Knesset rather than individual single-member seats. It's just what the People of Israel [or at the time, "the Jewish bit of Palestine"] wanted, perhaps. But, without having lived under such a government, I can still assume that an example like that supports Ricky's position? Again, even being a poli sci major for a while, I cannot precisely remember our discussions on Germany in the first comparative politics course I took. That was quite a while ago (I had been going to college part-time, and almost forever). But I would think (or rather HOPE) that our new at-large, party-list congressmen would have a sense of collective responsibility.
Hacker, I think it's blindingly obvious what 'strong government' means. It means a government that has the ability to enact its agenda. Parliamentary systems don't necessarily produce this type of government of course. Nobody would ever accuse Italy of producing strong governments for example. As a rule though, if a governing party is able to command a majority in parliament then they'll usually be able to pass most legislation, set budgets etc without the need for fudge, compromise and perpetual crises. Whether you see this as a good thing will of course be dependant upon how highly you value the freedom to act decisively over constitutional checks and balances. The American system was specifically designed to limit executive power and most Americans have been raised to view this as a good thing. It is a good thing I suppose, but it has drawbacks, which you can clearly see at the moment because right now America is virtually ungovernable
Yes, I can clearly see at the moment, and have clearly seen for quite a while, that there are indeed drawbacks to the American system. I still refuse to take the alarmist position that the present constitution [of 1787] is entirely "incurable" if it remains presidential.
I was told by one of my professors--definitely not a conservative Republican, nor the type of conservative making political decisions after having too many Long Island Ice Teas if you get my drift---that the founding fathers were less concerned with majority rule and more concerned with individual liberty. I would agree with that, and I do not accept the view some people have that majority rule necessarily equates to Liberty or Freedom (for just the individual OR the group as a whole). Be that as it may, I do share
some of your convictions that in a free society it is necessary to have a government strong enough to act in the interests of the majority of the people who elected it. And be
that as it may, however, you are not entirely correct in some of your statements about "the freedom to act decisively" [maybe I have misunderstood you when I say what I am about to say] is stymied by checks and balances (again, perhaps I misunderstood your paragraph above?) And, alas, I still contest you assertion that the United States is virtually ungovernable.
I also contest your assumption (or educated guess at best) that our system was designed to limit executive power. It was not. While Alexander Hamilton spends most of his time in
The Federalist Papers (the ones covering the executive branch specifically) desperately and vehemently convincing "Publius'" readers that no, the President of the United States was not, nor would he morph into, a Louis XIV-style monarch; it is still evident from reading
The Federalist Papers(depending on how much of them you read, and if you don't read many of them I cannot blame you!) as well as a copy of the Constitution of 1787 [as amended], that the executive branch did NOT worry our august founding fathers (or at least the 38 out of 55 of them who consented to sign the finished product). Not at all! If anything they assumed that, if any of the three branches of government were to get "out of control"---by that I mean aggrandize itself to the point of stomping on our liberties and freedoms (OK, the white people's liberties and freedoms)---or to run amok in some way, it would be the LEGISLATIVE branch, and NOT the presidency!
How do I know this? just look at the length of Article I, that which covers the legislative branch of the federal government. It is the most detailed and specifically-worded article out of the seven in the original constitution (it has been amended since then of course, but the amendments relating to the Executive, XII, XX, XXII and XXV, mostly deal with changes in the term of office, the mode of his election and his succession or "disability" if not actually dead; none of them actually curb the AUTHORITY or POWERS of the presidency!) It contains 10 sections. In comparison, Art. II (presidency) contains 4 sections and Art. III, (the federal judiciary) contains only 3.
OK, what's the Point, Mr. Hacker? The whole system was not designed to check executive power, but legislative, in general. The modern view of three, co-equal branches of government checking and balancing each other was not the original intent (remember in the first post of this thread, I said about how the original ideas of presidential, and even parliamentary, governments have "corrupted" over time---I wasn't talking about money, campaign finance rules notwithstanding). There is a whole section dealing with powers specifically DENIED to CONGRESS....the articles covering the executive and judicial branches do not contain any such prohibitions. Why? Because the authors of the Constitution of 1787 had their sights set on the powers of Congress, and keeping Congress from getting out of control.
And why do I say it's curable? Remember what I said about Maryland's state constitution? The states are mini-presidential systems in and of themselves. The governor of Maryland, thank God, does not even see the budget bill. Upon its passage by the State Senate (after beginning in the larger House of Delegates) it becomes law. Bazinga. Governor O'Malley cannot do a damn thing to it, as we must thank our lucky stars.
Of course, Maryland, I might point out, disproves your poinit that you need to get a single party to control the executive and legislative (and even judicial) branches of government. Maryland's government is not near as "efficient" as you gentlemen have advertised parliamentary democracy to be, and this is a one-party state. MD has been a "blue state" (Democratic) since Andrew Jackson was President. And with the current gerrymandering plan, there will be even less Republicans in both houses of the General Assembly to come even close to obstructing the will of the majority.
And yet, it doesn't seem to act quite as efficiently as you would assume it would under those circumstances....hmmmm......
P.S. Rickyp: you are doing a very fine job. Keep going, esteemed dictator to revise the Constitution of the Republic! I do not agree with all of your conclusions, but you've obviously put quite a bit of thought into it and brought up some decent points.
*Footnote: to avoid getting sued, audited, or my hot phone conversations recorded by CIA/NSA/FBI, data above courtesy of CIA World Factbook and the U.S. National Archives & Records Administration.