its a fair few quid to shell out :/ on something i know nothing about
We just got some 24" Dell Ultrasharp's in at the office. One thing I realized is that how hard it is to visualize a monitor size like that -- they were larger than I expected. I'd recommend at least taking a look at a 24" monitor in a local store just so you know what you're in for. I think personally I would not go beyond 22" for normal work.
Another potential issue: Depending on how close to sit to the screen, the viewing angle might become an issue. The outer edges of the screen may be at an odd angle, which can lead to discoloration on the far sides from your point of view. (Not an issue if you put it away from you slightly more)