I have never used the GroVia systems myself, because I found diapers that work great for us. However, I did look at their website and I checked out their products and even talked to a mama who knows about them and this is what I've deciphered from everything: The GroVia hybrid system (if that's what you were considering) has a great concept (the biodegradable inserts), but in reality I can't see that many people actually spending the time to take their inserts out to the compost pile and waiting up to three months for them to biodegrade. Not to mention the fact that the disposable/compostable inserts cost as much if not MORE than disposables.
Personally, I think the pocket diapers are the easiest to use, and one of the most economical. We use FuzziBunz Perfect Size and One Size dipes and love them! They're super easy to use, especially for daycare/babysitter use because all you have to do is slip an insert into the pocket and they're ready to go. I've saved hundreds of dollars so far, and would have saved more but I didn't start CDing until my LO was about 4 months old. They're definitely worth checking out IMO: www.fuzzibunz.com