Glad you found a solution to your lacking of tone. I have the PODxt as well, but really only use if for recording. I've heard of a lot of people doing the same thing you've done, but haven't had a chance to try it out for myself yet. At the moment, I'm running a Peavey Rockmaster tube preamp into the XT and then out to my soundcard. I'm only using the XT for cab and mic sims, and fine tuning with the post eq. This setup sound great, and is very versatile. It's amazing at all the different tones you can achieve with the Rockmaster.

BTW, Welcome to GT!