I had the Thule DH sidearm carriers mounted on the roof of my STI and thought they were fantastic
I thought they were great as I could drive the car normally
without the bikes bouncing up and down behind me as they are locked in solid on your roof. No issue at all fitting a Glory and a Sunday
plus you can lock them up too, if you need to duck in to a shop to get a drink
I also have a 3 bike Grip sport carrier but these were just easy to use as they were already mounted day to day. For big shuttle days then I would pull out the Grip carrier but if you are just taking 2 DH bikes the Thule roof racks are pretty practical.
The Q-spears do look pretty easy to use though
This was my Thule racks but if you are doing heaps of shuttling then maybe a Grip or Qspear is the way to go