The first 30in monitor I looked at was the Apple 30in Cinema Display back in 2005, and I was simply blown away by the amount of desktop real estate I had at my disposal. Of course the down sides were the fact that it cost over £2,000 and the number of graphics cards that could drive it were limited, to say the least. Apple also offered no screen adjustment for its 30in display, which meant that it always sat slightly too high for truly comfortable use.
Since then I've looked at several other 30in displays, like the excellent HP LP3065 and Samsung SuncMaster 305T. It's probably fair to say that Dell has done much to drive interest in the 30in monitor market too, by offering affordable options and driving down the overall cost of these super-high resolution displays. That said, I was somewhat disappointed with the image quality of the Dell UltraSharp 3007WFP-HC 30in monitor, although if colour accuracy isn't paramount to your needs, it does a reasonable job.
And that's the problem with 30in monitors in general - they're great for general Windows work, with the 2,560 x 1,600 resolution giving acres of desktop real estate, but when it comes to serious image quality and colour accuracy, they're not quite up to the job. Don't get me wrong, most 30in displays are great for Photoshop work, simply because you can work on very large images and see more of said images while you're editing. But serious graphics professionals would probably settle for less resolution and better image quality and colour accuracy.
That situation is set to change however, since sitting before me right now is the NEC MultiSync LCD3090WQXi. Anyone who's serious about image quality and colour accuracy in a monitor will probably have two names at the top of their list when buying a new display - NEC and Eizo. Both companies have built strong reputations for themselves in the worlds of professional graphics, image editing and CAD, offering truly superb image quality, but with a correspondingly high price. NEC's first foray into the 30in LCD monitor market carries on that tradition of quality over price point, which poses the question - is this screen worth the money? As with all questions of value, it ultimately comes down to what's important to you, but given the fact that this screen is aimed at high end users, I can't help but think that the price premium is worth paying.