It seems as though IPS displays have come down in price a fair bit. Looks-wise, you probably won't find anything better than the ACD. When it comes to build and image quality, most tend to do the trick. I think the ACDs have a higher native res than some of the cheaper offerings, but if you can deal with 1920 x 1200, go with non-Apple.
Personally, if I were to buy one today, I would probably go with the ASUS PA246Q
. I don't know if there are any offerings out there that offer this level of 'bang for buck'. (Admittedly, I haven't researched too much.) I have been nothing but impressed with ASUS products that I, or friends have owned. 3 year rapid replacement with free 2-way shipping seems like icing on the cake if you use the monitor for work. I think you could get two of these for roughly the price of a 30" ACD. That's 48" of real estate, and each monitor can display images from multiple signals(with quick switching, this could be an amazing feature.