Late to this thread so you may have already purchased a seat, but we are really happy with the Graco Slimfit. We have not used it in RF mode though (only FF harnessed and HBB). It is relatively slim, lightweight, no-rethread harness, converts from harnessed to HBB without uninstalling the seat....I could go on and on. I have two in my car and both my DDs, age 9 and 5, are very comfortable. DD1 is uses the HBB mode now except for long car trips; DD2 is still harnessed.