As mentioned, CRTs have pretty much zero lag. I can handle gaming on a modern TV, but it's definitely a plus for CRTs. On that note, maybe I should see what used Guitar Hero and Rock Band parts I can get for older consoles?
Though weight and space are real issues -- my CRT is around 36" and it weighs a ton. My dad and I had trouble carrying it from the car, while a modern 50" can be carried with one arm just fine. Also, I know it's going to eventually start breaking down, and the world's CRT supply will start going down. I almost wish somebody would start making lightweight CRT TVs to cater to the retro gaming crowd, but they would probably suck in some way and be really expensive.