Well, equalizers in general are, theoretically, room correction devices. The problem is, in the analog domain, every time you introduce another device into the stream, you take another derivative of the signal, and therefore introduce phasing problems. So a lot of audiophiles were against it, unless their room was severely "out of whack" (pardon the technical jargon). With the advent of such devices in the digital domain, this particular problem goes away. If I could afford it, I would definitely get such a device, as I used to have an equalizer in my system, and it did make a big difference. The other problem is that the "out-of-whackness" of a room is a function of where you are in the room. In some rooms (including my current one), those differences can be quite severe. Boominess, for example, goes up as you get closer to the walls, and even more so towards the corners. I've tuned my system to the sweet spot and refuse to listen critically anywhere else. This particular criticism is probably still applicable towards even the digital system.
DSP Devices for Room/Speaker Correction
The current issue of TAS has a review of the TACT RCS 2.0 DSP, a device devoted to correcting problems in the interface characterisitcs between room and speaker. There are several other models of DCS devices, such as the SigTech, Accuphase, and Perpetual. I long ago concluded that there was little more I could do to correct some of the anomalies in my listening environment, but the TAS article really caught my attention. I'd like to hear from others who have had some experience with DSP room/speaker corrections systems.