In many ways I think it would have been a good fit in Season One (as in the tone of the episode). Lauren is fast becoming one of my favourite characters, but it was pretty much the Santana show in terms of the entire episode. I'm not mad about Quinn/Finn/Sam, since it's practically a rehash of Quinn/Finn/Rachel. Rachel/Mercedes/Kurt, however, I can get behind very easily - it makes sense for the three of them to be friends, plus they've slowly sort of built up the friendship between the three of them since Sectionals. It makes me able to watch Rachel too, considering how I was on borderline hate at the start of this season. Nice to see that Blaine isn't infallible, too.
Glee's biggest problem is that the main characters are just wholly unlikeable, unfortunately. There's a reason Chris Colfer and Jane Lynch won and Matt Morrison/Lea Michele didn't - it's because the supporting characters are just so much better. Even when they don't have much depth (admittedly less applicable to Kurt and Sue now) they still tend to be the most entertaining things on the show. I'd much rather watch a Glee episode full of Mike/Brittany/Santana/Becky/Lauren/Karofsky than an episode about Finn and Sam. Quinn is excused because I sort of love Dianna Agron.
Also - I sort of laughed at the time with Tina's breakdown, but looking back at it, it was kind of out of character for her. Would have worked better if it was Santana faux-crying for Puck or something.