I had a really good experience with STI: http://www.stidelivers.com/IndustryS...otorcycle.aspx
I shipped my S3 from California to Georgia for $200-300 less than any of the uship bids. The downside is you have to drop it off and pick it up from a terminal, but that wasn't a big deal for me. I was 20 minutes from Sacramento and an hour from Atlanta. Anyway, I would really check them out if you're looking to save a bit of cash and don't mind dropping the bike off.
Oh, one more perk, which was actually critical for me, is that you can drop the bike off on your schedule. Any of the Uship shippers come over a range of dates. It's only a couple, but I had a really tight move schedule and couldn't risk them coming late.