Not mentioned often, but for me a major benefit (apart from the wow factor of filling your visual field) is the effect of having a wide sound stage match the visual stage.
Let me explain... Many people, myself included, have (had) a home theatre audio set up with front speakers widely spaced (often a necessity if they are not magnetically shielded) and a small CRT screen in the middle. Result: sounds impressive, but sound steering doesn't match the visual. I'm now watching a 6'6" wide image with the main speakers virtually touching each side of the screen. Result: wide soundfield as before, but the integration between sound and vision is now obvious and IMO so significant that I could never go back. In other words, when someone walks from left to right, the sound follows that person accurately and convincingly. Likewise with action scenes (e.g. the F18(?) down scene from Behind Enemy Lines).
Believe me, it really makes a difference. You can get accuracy of sound panning with a 50" plasma or a 36" CRT and magnetically shielded speakers by placing the speakers close to the screen, but the impact of the soundstage is considerably reduced due to the smaller physical width of the front three speakers. Nothing beats a large screen and correspondingly wide soundstage.