I've had a roof rack going well on 10 years+

One thing not mentioned thus far... you will see a drop in gas mileage with the rack on... even w/o bikes. With bikes, you'll see another drop.

I'm assuming the trailer hitch racks also experience some amount of gas mileage degradation when all the bikes are on, but I would suspect it's less than a fully loaded roof rack. Ex: I was experiencing 4-5 mpg less with a fully loaded roof rack over no rack.

Next vehicle, I'm likely going to go the hitch rack route... 1) I avoid the mistake of driving into the garage, 2) gas mileage improves, 3) soooo much easier to take it off and store in the garage as opposed to the roof rack - which I just go ahead and leave it on all the time.