Interesting numbers, you are right, first week sales say nothing about the overall performance of a title, to much other factors are influencing these sales and it seems, that a title like MGS has reached it's first week potential with it's 2nd incarnation. It would be interesting to compare the overall sales for these titles to see how they did in the end and to see how much first week potential tells about how the title does in the end.
Let's wait and see, how New Love Plus performs in the end.
It would be awesome, if it would reach the numbers of Love Plus+.
Eh, I don't think his point was that we should dismiss first week numbers; the LTD numbers for those games are also very close despite difference in install base at their release
Metal Gear Solid 2: Sons of Liberty 798,185
Metal Gear Solid 3: Snake Eater 819,807
Metal Gear Solid 4: Guns of the Patriots 706,461
Metal Gear Solid: Peace Walker 790,053
(can't find numbers for MGS1 but I belive it was around 800k as well)