it helped mine, but not really a night and day sort of thing. At this point,so many years later, just having any new mounts would probably be a huge upgrade, LOL.
I believe GM started using the hyd mounts on the LMM chassis but could be incorrect. I believe the TSB is from the 09-10 era. I recently helped a buddy one night after work put in new mounts on his 03 crew cab. He sourced the front four and I sourced the rear two from GM and he went with the hydraulic mount. It helped a bunch but like James said, there's only so much that can be done to account for the expansion joints in the freeway.