I did an unhealthy amount of research on hitch mount bike racks and I ultimately decided to splurge on the Fulltilt 4. I am glad I did. It came down to the Fulltilt and the Swingdaddy which basically means ease of installation vs. the ability to access the trunk/hatch with the bikes on the car respectively. I am very glad I went with the Fulltilt as it can be installed/uninstalled in about 20 seconds. Another benefit vs. the Swingdaddy and other accessories is the the built in lock which saves the cash for an extra accessory, but more importantly it is built in and nicely stows. I would highly recommend the tubetopper accessory or equivalent for any non straight top tube bikes (most aren't).
This rack is worth every penny