I have this one that I picked up from a guy off of KSL last year. Before getting it, I would borrow a buddies all steel hitch hauler so I have used both types.
http://www.amazon.com/Aluminum-Motocross-Mounted-Carrier-Receivers/dp/B001IUV1CM
It carries my 300 well, and is light and easy to handle. There are pros and cons with the design.
Pros:
Super light compared to the steel ones.
Having open slots, the bike tires fit in the openings and feels very secured.
The openings also allow for easy tie down placement for additional ties.
Ramp is light and has its own storage location.
The anti-sway collar works, but is not robust.
Easier to store (flat, hang on garage wall) than the steel ones I have used.
Cons:
Aluminum may not hold up with a heavier bike.
Ramp is WAY light. Not for heavy bikes.
Anti-sway collar can be a pain and requires tools. (I own a Jeep, therefore I carry tools)
Open slots makes it harder to roll bike on and off. (Especially if your car receiver is up high and you ar short, like me)
I gambled with buying this hauler, but it paid off. I have an enclosed trailer I can drag, but for quick rides, this hauler works very well and has probably paid for itself in the fuel costs already. I got it for $90.