The biggest issue you're going to have is that the native resolution of a 23" flat panel is enough to choke just about anything short of a 6800GT SLI rig if you're playing HL2 or Doom 3. I hear it scales down to lower resolutions rather nicely, so that is always an option.
Also, if you're playing a game that doesn;t support widescreen aspect ratios, you're going to have vertical black bars on the sides - leaving you with about the same viewable area that the much cheaper 2001FP has. Of course, most of the new games support widescreen aspects so this is becoming less of an issue.
Before I'd get an Apple display, though, I'd hang tight and see if Dell puts out a 23" widescreen display sometime soon (as they are rumored to be planning). Aside from the styling of the monitor, I personally find the 2005FPW to be a superior monitor to the 20" Apple Cinema display as it has a better contrast ratio, has more inputs, has better positioning of the USB ports, and has a stand that supports rotating the screen into portrait mode. Plus it is a heck of a lot cheaper, even after the Cinema Display price cuts. Once the backlight issue is fixed, the physical appearance of the Apple monitor will be the only thing it really has going for it over the 2005FPW. I'm sure it is going to be a similar situation when Dell eventually puts out their 23" widescreen, so I'd be cautious buying an Apple display right now.