We bought the 1UP about 3 years ago and love it as well (I learned of it a year prior to it being mentioned here from a mountain bike forum). We used it on the back of our Casita, and was MUCH better than the Thule we had before that banged the bikes together and wore off a lot of paint from that.
However...one word of caution. You need to check before you drive off that the arms that fit around the tires to hold the bike on the rack are tight against both tires. I must have overlooked that one trip. When we got to our NH campground 150 miles from home, I found out that my son's bike was gone. As in fell off at some point on the route.
My wife said it looked like the arms were not firm against the tires when we were getting ready to leave, but thought I wasn't done with it. If there is any play where the bike tires can move forward or backward, the bike can come loose and fall off. We have used it since without issue, as I somehow learned to check that.
1UP does sell locks that go through the spokes of the wheel and attaches to the arm, which would prevent that. I wonder how many people like me had that happen and let them know?
Other than that, and it being 100lbs for our 4 bike carrier (requires 2 people to put it on the trailer/truck) it really is great.
Well, except for that one of the arms sticks when folding it down when no bike is present, which it makes it hard to collapse (1 painful click at a time).
But other than that....we really like it!