Pros: Front, back, and hip positions; very comfortable
Cons: straps slide off; hip positions is awkward
We love our Ergo. Even without the infant insert, I've used it often since my son was just two weeks old. The weight is distributed really well, and I don't get back pains even when I wear my son on long-ish (2-4 miles) walks. The front pockets are really great- the pockets are big enough for a wallet and keys.
My only complaints are that the shoulder strap slips off. I have tried tightening it in a variety of ways and this still happens. Also the hip position is awkward to get the kiddo in and out of.
Overall- great carrier. Seems pretty durable. Very comfortable, even as my son is approaching 30 lbs.