My wife's car has a receiver mount rack, mine has a Yakima roof rack-- my car is far too low to mount a receiver. If you're short, a roof rack might be an issue. I put two bikes and all of the bike-related stuff on the roof for a 1,000 mile round trip to Mammoth, had zero issues.
That said, I would still recommend a receiver rack. For what even just the bike trays cost for a roof rack, you can get a really nice receiver rack (like a Kuat.)
__________________
