I won't convince you, but I can give you negative views of it:
a) You won't be able to run Shogun 2 with max settings at 1080p. The built-in benchmark would refuse to run, giving you an annoying error message of "insufficient vram", while the game would actually reduce your graphics settings in stealth. You could override the script file to avoid such problems, but you risk suffering from lag spikes due to vram shortage.
b) You shouldn't be able to max out GTA 4 because the game engine has a stupid vram check. You'll need to hack the game in order to bypass the vram check. Again, you risk suffering from lag spikes. Also I read somewhere else that if you install any mods such like ENB, 1.25GB vram would lag like hell.
c) You also risk getting lag spikes in Metro 2033, Crysis, Crysis 2 DX11 with high res texture, future games etc due to vram shortage if you set max settings.
d) If you lower your graphics settings to a certain threshold below which the vram usage is safely below 1.25GB, in most cases you get a framerate much higher than 60 fps. Unless you are using a 120 Hz monitor for 3D or something, I regard it as wasting GPU power.
I don't recommend putting GTX470 into SLI, unless you can get it for a cheap price.
Just personal opinions. Feel free to troll.