I have one. Joey likes it okay. He's big enough and moves enough that he was out of the newborn hug hold really fast, and that was a bummer. I personally wished I would have waited to try it out with him with a borrowed one first.
Usually I feel like I don't have enough time to put it on perfectly, get him in comfortably, and be relaxed enough to not freak him out. I think I'd like to get a different carrier, perhaps an Ergo.
But I'm one of the few that don't really care for it. Most of the moms that I know that have one LOVE theirs.