Digital room correction, any recommendations?

Stereo or 2 channel?

I tried a few. I never failed to notice a slight reduction in resolution, despite the improvement in bass response, etc realized via digital correction.

I recommend judicious use of room treatments first, and if that fails, I'd try the digital route.

Just my experience; I'm sure many others will disagree.

Two-channel.

Do the room first, you may not need anything else.

I'd highly recommend acquiring software that lets you see the frequency response and reverberation times of your room. Then you can apply room treatments to deal with the areas which can be fixed.

As for digital room correction, I've tried Z Systems and Audyssey and most recently Trinnov. I use a dedicated Trinnov unit that does 4 channels (recently released). I auditioned it for some time in my system before decidig to go ahead with the purchase. It has proven efficacious and worthwhile and I am quite critical of things that alter timbral purity, resolution, etc. One of the nice things about the Trinnov is that it has a highly detailed interface that provides a tremendous amount of information as to the sound in your room and also the means to make fine adjustments over a variety of parameters. The downside is taking the time to understand what you are doing.