Doubletrack is fine. Because of the bike holding mast in the middle, it sits kinda far off the tail of the car, so getting into the trunk/hatch can be tricky. Even with bikes off, and the rack folded down, your feet are still 3 feet from the hatch, so loading/unloading heavier things can be tricky. Non issue with a pickup, as you can approach from the side of the bed. The T2 sits a bit closer, has better security, but costs quite a bit more.
The other thing to consider with the Doubletrack is that the bike is held by the frame, in basically the same place every time. Over time, the small amount of play will dull/scuff the paint. Mostly cosmetic, but right in the middle of the top tube, so noticable. Again, things like the T2 hold via the wheel, so any wear on the bike is via tire, which is less of a deal.
Thule makes fine products, from a use/reliability stance, I wouldn't be too worried.