Gdiapers suck IMO. Our neighbors tried them and found that they are problematic. They only flush down certain toilets and are not very absorbant. They also contain gel in them just like 'sposies. Personally, I would go with 7th Generation 'sposies for the trip. They're made from recycled materials, are not perfumed, are unbleached, and work pretty well.
I heard from a mama that uses them that they suck -- she showed them to me and I was not impressed. I don't htink they hold urine very well -- she wanted to get started on cloth since they were such a failure. We're traveling now, too (moving) and I just am using regular sposies for the week. DS seems OK with it so far (no rashes, etc.)
I bought a starter pack and I am not impressed. There is a lot of plastic touching baby. The diaper didn't clog my toilet but it did make it flush slower and I had to plunge it. The outer cover may make a good swim diaper though. I'm going to try it this Tues.
I use them and love them...BUT I don't use the flushable inserts (never used a single one, and after reading the replies, don't think I will!). I make my own cloth ones. But I think that they're a great cover/liner for the cost!!