The show is a pretty standard sitcom that has a story or theme of the week that the characters have to navigate. The comedy style is much like the other mockumentary shows like The Office and Modern Family in which the jokes are either set up or performed, and then there is some kind of follow-up, either a reaction shot of characters in the background or cutting to one of the characters being interviewed by the documentary crew, or something like that. The humor is all over the place, given the wide range of acting styles of the cast members. Ron's humor is much more gruff and deadpan, while Leslie's is more chipper and upbeat. Chris Pratt does a great job playing a dimwitted doofus who thinks he is a rockstar, and pretty much everything Aubrey Plaza does is awesome.
The complete series set is just the individually packaged DVD seasons in a box set. There is nothing new if you have already purchased the individual seasons. There is also a blu-ray version of the complete series set out there that, from the looks of it, has the same overall content as the DVD set. The big reason to get the physical discs (beyond just preferring them over streaming, as many of us do) is for the extras. Each season has a bunch of extras, including commentary tracks on many episodes, deleted scenes, gag reels, fake PSA spots, and more. One of the best extras is a great joke that Chris Pratt made during the comeback story scene that cracked everyone up and is included in one of the gag reels.
Overall, the series is wonderful. It is very well-written and acted. It did take a couple of seasons to really find its footing and did have some cast turnover after season one. But, once it found the formula that worked it was strong all the way to the end. There were a ton of great guest stars, including people like Will Arnett, Tatiana Maslany, Jenny Slate, Patton Oswalt, and even the occasional DC politician. While the entire cast is great, Aubrey Plaza and Nick Offerman were the standouts to me. His scenes with his real-life wife, Megan Mullally, who plays his ex-wife, Tammy II, were pure gold. While it is a show about politics, and certainly, it was easy to tell the political leanings of the showrunners, it made fun of both parties, Democrats and Republicans alike. And it holds up well even after having been off the air since 2015. I highly recommend it, especially if you like political comedies.