been running one since they first came out this spring. a significant improvement, imo. the bronson suspension leverage rate curve exacerbates the crappy characteristics of an air shock - i.e, high initial breakaway, moving into a wallowy mid stroke, ending with a significant end stroke ramp. with the stock shock, if you try to tune suppleness (i.e., lower pressure), you blow though the mid-stroke. pump up the pressure to support the mid stroke, and you lose end of travel, and plushness. the fat negative spring on the corset gives a very supple beginning stroke, and allows higher pressure to support the mid stroke nicely. i found the shock works well without any internal volume spacers. results in a very plush, quite linear shock - coil-esque, even. very nice.
my stock damper recently blew it's guts out; just replaced it with a pushed ctd (with the new black shock body). no rides yet.