Ive heard that there is ghosting visible on the dells, 16ms is quite slow indeed!
quoted response times are an indication of the screen generation and not actually related to the actual response speed suprisingly enough. You wont find many screens with response times even remotely close to the quoted values.
The bigger the screen, the slower the response time, the worse it is for games, so you really need make a comprimise between how much you want a mahoosive screen, and how much you need fast ghost free games.
If response times were accurate (i.e. the time it takes for a pixel to update) then it would make no difference how big a screen was. It would still take that amount of time to refresh wether it was a 1 pixel screen or the size of europe.
Best way to judge is to go on personal opinions. I cant actually see any ghosting on these screens on movies, tv, football games, world of warcraft, etc although going on what Punkd said its probably apparent on things like counterstrike (never checked tbh). Short version is - ignore given response times - theyre utterly meaningless.
Just a fyi - I can run most games I play at reasonable settings and 1920*1200 on my old PC without too much trouble (xp3500, 1 gig ram and an ati x800xt). On this screen size just make sure the screen youre getting can transform images to HDTV resolutions in case you ever want to hook it up to a console etc.