I used one of those style racks for many years (like the first 30 years of riding mountain bikes). They work just fine. Two things I was not a big fan of. 1 - you have to strap the bike frame to the frame tube to keep it from swinging and getting beat up on rough roads. 2 - if you are mounting more than one bike it takes a little bit of figuring out which one goes where so the important stuff (chains, shifter levers, brake handles, cables) aren't rubbing or getting crushed by the other bike.
I switched over to one of the ones the tires sit in to a tray and really like it a lot better. Here is the one I got:
https://www.thule.com/en-us/us/bike-rack/hitch-bike-racks/thule-t2-classic-2---2-_-1689772Much faster and easier to get the bikes in. You push down on the front locking bar on to the front tire and you are good to go. Bikes are separated and don't move. My older rack was pretty old so they may have made improvements to them but this has been my experience.
