I have been using therm-a-rests since probably 1996 or so, and have finally gotten so frustrated with putting holes in them that I have resorted back to closed cell foam. I know, I know, the comfort is not there, and neither is the compactability, but weight is on my side there.
While I was in the army I put a bunch of holes in my therm a rest by dropping it on a thorn bush (yeah I know it was dumb) and spent about three months patching holes before I finally got it all plugged up. Don't get me wrong, I am still using one, but if I put a hole in this one, it is my last. I value durability and reliability above everything else.