On the topic of the Innicyle (rather than a debate between threaded and threadless stems), I have had one for several years, and it's lived on a couple of bikes, most recently on the bike I rode in this year's Cino in Montana. A problem I've had is that I sometimes can't quite tighten the wedge within the steerer tube enough to prevent the unit from rotating while riding. For Cino, I tried applying some Park Tool SuperGrip to the inside of the steerer, and that worked for awhile, including rides up to Cino and through most of day 1, but by the end of day 1 and at the start of day 2, my bars were flopping around such that I thought I'd have to DNF. Instead, I tried loosening the wedge bolt and then tightening the beejeezus out of it, and it held for the rest of the ride. In fact, getting the Innicyle unit out of the steerer tube once I was back home required lots of effort. I've seen some similar complaints with the early generation Innicyle on this forum, so I'm guessing they somehow addressed the problem in later iterations.