I'm a proud owner of a Saris roof system (upright bikes and snowboards) for the past 12 years. Same rack, just a bit faded. Rock solid and I've never had any problems with it. I'd definitely go with Saris again (which I might - need new load bars for a new vehicle purchase). Definitely user friendly and a breeze to install, use, and remove.
As for hitch vs roof... I don't know much about hitch racks, but they have to be easier to load and create less drag on your vehicle. I'd also venture Maybe also more protected from road debris (stones and such)and insects, especially at highway speeds. I've also heard that excessive highway driving may prematurely dry out your components (headset, sprokets, pedal bearings), but I question that...