I have an 03 TB 4x4, not "really" for serious off-road use, but I do drive it wherever it has to go. It is modified with PCM flash, True-Flow CAI, 245 Cooper AT tires, and a few other touches. For the rough stuff, I run more hard-core equipment, but I am a total off-road enthusiast and I'm excited about the number of off-road Trailblazers that are now starting to be built. With the cost dropping, and the platform aging a bit, we'll only see more of this.
Next comes the SAS and rear axle swaps for larger tires, etc. Can't wait!

I hail from Louisville, Kentucky, was raised in Wisconsin, and off-road all over the United States. I'm also one of the co-founders of UCORA.org, the United Christian Off-Road Alliance, an alliance of clubs, forums, groups, and individuals dedicated to the off-road sport in a family-friendly way. We're now in our 3rd year of hosting national events. We just finished up our Crawl 4 Christ event at SMORR in Seymour, MS with 114 rigs in attendance. Had a blast wheeling with the Texas, Missouri, Oklahoma, and Kansas guys! I'd love to see the Trailblazer crowd show up at one of our events.
I bring a lot of fabrication and off-road experience to the group, and I try to share. See you guys out there!