Pros: I love that I can rotate two covers for each of the kids all day long. If a liner gets dirty I just rinse it out, toss it in the laundry, and get a new one. In addition these are almost blow-out proof. I remember washing at least one onesie a week when Izzy was in disposables and still EBF. Johnny has had one total. What the liner doesn't catch the covers do a good job of catching. I usually end up cleaning a minimal amount of poop off a cover once or twice a week. To me that's amazing. Also, these are pretty trim cloth diapers meaning that pants fit better and my diaper bag is smaller :)
I love the flushable inserts. We haven't had time to build up our cloth stash to a reasonable size, so we've been using flushies from time to time and overnight. They work wonderfully overnight for Johnny when paired with a cloth insert.
Cons: There is a learning curve. Most notable is figuring out how to fasten the tabs in the back properly when your child is laying on his/her back. It also takes some practice to figure out how to get the liner to fit properly in the crease of the thigh. This is very important for preventing leaks and blowouts. Also, while we've found the sizing to be pretty good on Izzy, we've hit some trial and error with Johnny. His belly is on the chubby side and while he's outgrown the small covers he's just a tad to skinny around the thigh for the M/L liners to make a good seal. The result is a lot of leg blow-outs. We've resolved this by using small liners with medium covers. Seems to work for the most part.
Side notes: we made our own cloth inserts and chose not to use the gcloth. I made some microchamois/microfiber/hemp fleece inserts and after using them for a month they are my least favorite. I love Johnny's bamboo velour/bamboo terry/hemp fleece inserts. They are extremely soft. We also have some of these Zorb inserts by twinkletoesdiapers in M/L and they work beautifully in gDiapers with less bulk.