Let me start out with the fact that I've been riding for 10 years and consistantly get 50+ days in per year. I've ridden traditional straps, switch step-ins and now the 2007-2008 K2 Cinch CTS. Also note I currently live in the midwest with short runs, so a little speed at the top means more runs for me. I really do like them, but there are a few cons as well and I'll start with those.
First, they are heavy, not super heavy, but you definetly notice it on the chair lift, but not at all when riding. Second, they're bulky. They do fit upsidedown on my roof rack (something Flow can't claim), but barely. Also, I'm a small guy, 8.5 boot, but I still need a Large binding since mediums don't fit over an 8, so this means extra weight for me when I'm used to medium sized bindings. Third, they're expensive. Lastly, they take a bit of muscle to pull the high back up. My girlfriend got the female bindings and has some trouble with this, but for me it hasn't been an issue.
Now to the good stuff. They're fast. not as fast as my switches, but darn close. They're super responsive. If you adjust the strap with the back up, then drop the back and give it another click on each ratchet you can get them super tight and get great control. I also think they're easier to get into than the Flows two of my buddies ride with. This is thanks to the pivoting straps when you drop the high back. Another benefit over the flows is that they have a heel cup for extra stability. But all of this comes at the price of a little added weight. I also really like the fact that I can use them like traditional straps in deep powder if need be. I would recommend spending the money on the mid range CTS over the CTL though, the straps are definitely nicer.
I also wanted to note that I've been hitting the biggest jumps in the park (which aren't too big yet since it's early season still, maybe 30ft gaps) and haven't had any problems with the bindings when landing as others have mentioned. But those sound like they were from previous versions and K2 seems to have worked some kinks out this year. People have also complained about a metal tab that breaks, this has also been removed from the current model and I haven't had any problems with the bindings so far (I've been out on them about 10 times this year). Overall I'd recommend them if you're looking for a faster alternative to traditional straps. If I lived in the rockies though, I'd probably have saved a little money and stuck with traditional straps.