I really like them. I had the mids on last season and now put on highs. Just reving the bike in place I could hear the difference in the pipes. I don't have any seat time on the highs, but the mids were on all last season. And they weren't fast pipes, but the power band came on so smooth you couldn't really hear it like a normal 2stroke. As for feel, they top end wasn't anything to write home about but the bottom and mid. It would just pull extremely hard. The power was very usable in tight trails and very easy to manage the bike. The transition was smooth and felt almost like a 4 stroke.
I'm a believer in these pipes. I'm hoping for the same results with the highs. But just that, higher RPMs.