I currently have a 55" LCD, but I'm planning on replacing it with a 70" 3D capable TV around Dec.-Jan. (possibly the Sony R550A). Obviously, it's not just for GT6 - it'll be a nice general upgrade for movies/tv/gaming. I'll have to replace my TV stand and get a wall mount, so I'm saving up so I have enough for everything I need.
i built myself a PVC rig last summer with a T500 and TH8 shifter and I have a 32" Sony 1080p/120hz TV. Wish it was bigger but it'll do for now until I'm out of college
Your brain adapts to the gaps pretty quickly and you don't even notice them. It enhances the gameplay greatly, I never felt a sense of speed from a video game until I got the triple monitors but now I really get the feeling like I'm moving and moving fast. You can also look further into the corners which is a great benefit for consistency and accuracy, any driving coach will tell you it's incredibly important to look ahead to where you're going and with the side monitors you can actually do that.