we have a Saris. It hold the bikes secure but because of a back mounted spare we had to put an extension on (this allows wobble in the rack, not the bikes).
Also I found that filling the maximum number of bikes there were issues. Very tight fits and a game plan as to which bike to put on first. I have been loving my roof mount in comparison, great money spent. Bikes secure, no wobble and can lock the bike rack much easier. It required an extra long cable lock and a secondary cable to lock 4 bikes on the hitch mount and the hitch to the car. Roof racks require so much more effort to get off and with the bikes locked to the rack, too much time elapses for anyone to "wonder" if a theft is occurring. IMO