I'm using gDiapers for my son, and we love them! IMO, they're the perfect hybrid between sposies and cloth. You can go all-cloth with them, like you said, with cloth inserts instead of the flushables they sell. We use them exclusively with the flushies, and they work great for us.
Ninis1656, the liners do stain somewhat easily, but it is very simple to remove the stains. Hang them in the sun while slightly damp, and the sun will bleach the stains right out. You don't even have to put them outside, even a windowsill with sunlight coming in will work just fine. I find it very easy to do. Also, they last much longer for me if I wash them in a mesh lingerie bag. I bought a couple at my local Target for about $3 each. Also, the gDiapers yahoo group is an amazing resource for G users. They can help you with just about any problem you'll encounter with gDiapers.
http://groups.yahoo.com/group/gDiapers/ I hope this helps!