If there was a problem with Dave as a character, it was that there were very few problems with Dave as a character, as well as with Louis CK's portrayal of him. He was funny largely for the same reasons Hank Hill was funny, but he didn't have much in the way of a character flaw. This resulted, unsurprisingly, in a character that fans (the few of them that exist) really liked. But he wasn't meant to be a permanent character, and when the time came to write him out of the show, the writers had a bit of a problem on their hands: how do you replace a character everybody likes?
The solution they came up with is kind of brilliant: replace the somewhat too perfect character with a parody of a too perfect character, such that his one flaw is actually that he's so perfect that it gets to be kind of humorously obnoxious. How can fans really complain that Leslie's taking a step down with Justin when he's a philanthropic lawyer who travels all over the world and knows everything about everything?
Granted, I may be overstating the problem the writers faced here. CK was on the show for such a short while that fans may not have gotten so attached to the relationship that this was a big deal.* Other shows have faced more pronounced versions of this problem, though. I'm thinking specifically of Buffy the Vampire Slayer, which solved the problem of replacing Oz by turning Willow gay and bringing in Tara, who was just as overly perfect in her own way.
- This is the second episode this season to use the dinner party trope, and we're only halfway through the season. It doesn't really matter as long as they're well-executed, but it seems odd that the writers would use the same trope twice so close together.
- April and Andy should get married and have lots of weird, funny babies.
- Deviled eggs are absurdly delicious. As such, I can't really fault Ron for wanting to keep them all for himself.
- As for Leslie's use/abuse of the rec center instructors, it was the kind of thing that easily could have gone off the rails, but fortunately didn't. It also highlighted yet another way in which Leslie is different than Michael Scott: she takes immediate responsibility for her actions and rectifies them as best she can.