I have done it both ways. The easiest is to load the bikes then raise the bar. I have never found it easy to tie bikes down no matter what the rack. I load 3 bikes on the rack, and toss my son's small bike in the bed of the truck (much easier than strapping down).
2010 Jayco Eagle Super Lite 31.5 FBHS
08 Chevy 2500HD LTZ Duramax /CC/SB/4x4