I ran Rockstomper mounts. They stiffen up the drivetrain alot, you wont get any movement in the tcases/tranny but they will vibrate the whole truck.
On the trail they are great, you dont notice the vibration much. On the road they suck. Simple as that.
I swapped them out for stock motor mounts when I swapped in a newer 22RE. Running a budbuilt with dual tcase mounts, now my drivetrain shifts alot. From what I have seen, I think a front range tcase crossmember is the best compromise. It will stiffen the drivetrain enough and save the stock motor mounts but not vibrate the whole truck like the stiffer poly motor mounts do.