Not worth the extra dollars you save.
I had a litany of problems with booking with Avis, culminating with their being unable to book my car due to the type of Mastercard I had, then tried to bill me $100 as a no show fee. I got them to reverse the charges but it will take up to a week to process.
Added to this was some of the worst customer service I've ever experienced. Rude, late, taking on their personal phones and listening to their iPods.
I will never try to use Avis again. Going to stick with Enterprise from now on.