In my opinion multi-monitor gaming and 3D gaming are like fluffy dice. Some people like them but others cannot see the point. I cannot see the point, so 3GB and 4GB cards will be overkill for me. Give me a 1.5GB 7970 (when they arrive) or a 2GB GK104 (I refuse to call it a GTX680) as either would serve me fine at 1920x1200. With TXAA, much less VRAM is needed than FSAA and it apparently gives much better results anyway.
Having used both over the past six months (triple monitor and 3D) I can say that triple monitor isn't something I wanted to keep. I ended up breaking the array down after about two weeks, it really bothered me that much.
The worst part of it was how it zoomed in the two side monitors no matter what game you were playing. Due to this Fallout 3 was pretty much pointless, as the two side monitors were woefully inaccurate on things like enemy distances.
IE - If I looked to the left monitor and saw a Deathclaw it looked like it was right on me. Turn around and bring it onto the middle one and it was miles away. This made it kind of stupid. Not only that, but the textures on the side monitors were stretched really badly. So whilst it was quite nice I just spent the whole time staring at the middle monitor, making it all kinda pointless.
It was like this in FPS too.
3D however? whilst it isn't great for all games in certain games it's absolutely fantastic. Left 4 Dead, for example, is seriously enhanced by it. It makes using a melee weapon so much more accurate as distance is much easier to judge when you have a full 3D model running toward you. Because the screen has depth it is easy to see just how long, for an example, the Samurai sword is, making it far easier to time swinging the thing at an incoming zombie.
Plus, 3D is absolutely tons of fun. Throwing a pipe bomb and then standing as close as you can and watching the spray is absolutely hilarious, and things like sparks falling from the overhead power cables are really cool.
It definitely adds another dimension to gaming (pardon the pun) and I really love playing most of my games in 3D now. I didn't bother to play Alan wake, however, because of that horrible warping thing it does. It made me feel quite ill. But, it's a simple matter of not launching Tridef and not putting the glasses on and you have a completely normal desktop set up.
Again, try 3 and you'll never come back!
I thought it was nobbish too at first
It is. And when you start to notice the flaws you then have to continually keep convincing yourself it isn't nobbish. Which for me is very very hard, so I took them down and broke out the Polyfilla.