Throwing in my two cents... the first season and a half are excellent, but they end up overextending the concept, getting a bit repetitive and implausible. They tried to revamp things late in season 2, and they had good reason to in my opinion, but what they ended up with was not an improvement. Seasons 3 and 4 are uneven, unfocused, and way too dark and angsty. Season 5 was a major improvement, because they remembered to start having fun with the concept again.