Thule Hull-a-Port Pro (835)
I have 2 sets on my Scion Xb, hauling 2 12 foot kayaks. Have taken it up and down twisty back roads, and on the Interstate with absolutely no problem. Installation was really no problem, although getting the bolts through their holes during pre-assembly required a hammer - not exactly the easiest process.
On the car they hold the kayaks very securely. The straps and ratcheting front/rear tie downs are perfect and easy to use/tighten. The folding feature is great, it allows me to get my car in the garage without removing the rack - very convenient. I do wish the holders came with a way to lock them to the bars.
Loading is fairly easy. I'm 5'11" and can load both boats easily after a day of paddling. My wife is about 5'3", and there's no way she could load the boats, so if you're short these probably aren't for you.
All in all for what they are, I couldn't ask for much more. The Thule Hullaports are a great product! We mounted them on our Yakima roof-rack and have carried two Bic Sport kayaks around Southern California kayaking locations (lakes and the ocean). They are solid, stable, and support the kayaks quite well. I like the fact that they included the bow and stern tie-downs. Nice touch! Here’s a loading tip we discovered. We have a tall vehicle (a Honda Element) and, since we’re 5-8 and 5-7 respectively, we had a bit of trouble getting the kayaks up into the mounts at first. Until we tried turning the kayaks upside-down and kind-of rolling them into the mounts. Worked great! Now we can attach the mounts and load both kayaks in under fifteen minutes. You can see pictures of our set-up at: http://www.annandave.com/long_beach/.
I highly recommend these mounts.