Nemohunter,
All of the barrels you mentioned seem to be doing very well, but there are others out there. I've been thinking about rebarreling sometime in the future, but my Hart 6 groove 1:16 twist is still banging out 250's (51 so far) after 3 years and over 20,000 rounds. I put one wet patch and 4 dry ones through after every target, shoot 5 foulers off target, and the 6th shot is just where it should be, every time. When the time does come, my 40X will probably be wearing another Hart barrel. The hard part will be deciding just when it IS time. Good luck with whatever barrel you choose.
Todd Banks