I've had the Timberlines for a couple years now, I'd guess I have a couple hundred miles on them at this point. They still feel like walking on 2x4's to me compared to my Vivo's. The sole/shank feel very hard to me, even with Lathrop's inserts and what I would think is a sufficient amount of break-in time.
I always pack them when I expect to be in alpine or rocky terrain, but otherwise don't find myself reaching for them in most conditions these days.
That being said, I have never owned the Beartooth's and cannot give a side-by-side comparison on if they are less 2x4-ish than the Beartooths.