You can definitely return them, same return policy holds as with regular merchandise.
My experience has been mixed.
The first AS IS bag I ordered was perfect, but the bag wasn't good for me for other reasons than condition. So, I returned it.
Then I ordered two more "as is" bags. Both had glaring defects, a chip in the leather that was very noticeable, and some peeling on the trim of the other one. They were expensive bags even at "as is" prices, so needless to say, they went back.
I read tons of positive posts by people who did very well ordering "as is" bags, so it's just a gamble.