The GroVia AI2 is also a hybrid system. Click to view larger.
Pros of hybrids:
convenience of disposable inserts
great for travel
no need for carrying wet bag with disposables
Cons of hybrids:
disposable inserts can be expensive
flushable inserts are not 100% flushable
some brand's inserts can leave sticky residue
As I've mentioned, we have a nice stash of GroVias. I've never needed to buy disposable inserts, but we may end up getting some in June for the long car trip up to our home state. It'll be nice to have this option while we're on a mini-roadtrip!