I have one and it is okay, but I don't like it as much as the old Q-tower/roundbar racks they made. The old system only had to be adjusted the first time it was installed then it was a matter of minutes to remove or install it at will. This new Baseline system that fits the Yaris has to be adjusted every time as a part of the installation process.
Getting this new rack on and off the car is a such a PITA that I just remove the back seats and shove my kayak through the trunk. Taking out the seats takes less time than installing the rack and I don't have the wind resistance up top. My kayak is just over 6' and I don't even have to move the seat. I expect it would work with a kayak up to about 8' long as long as the passenger seat is all the way forward.