I live in an area with a lot of great XC trails, some of which are pretty gnarly, but only a few flowy, sendy, 1-way downhill runs. I had a Tactic II for a while -- until the plastic line on one side of the adjustable fit dial snapped. I'm not sure how it happened, but it wasn't a crash. Anyway, I was going to try a different helmet so I shopped around some LBS, but none fit my Big Head as well as that old Tactic II. So, I decided to give the Tactic III a try. It fits smaller, but adequately. I'm on the sixth and final height position of the adjustable fit system, and it feels good with my Pearl Izumi skull cap underneath, but when I had the Tactic II, I used an intermediate position. Those with VERY large craniums should look elsewhere. Also, I preferred the matte white (with black buckles) of the Tactic II, but the gloss white (which fades to grey in the back) of the Tactic III is okay, I guess. The helmet has a quality feel and good ventilation for the $$$. I hope it lasts a while, like the Tactic II did.