I watched this the other night, and I really enjoyed it, it was very entertaining. I highly recommend it to anyone who likes old SNL, it hits you with nostalgia. The casting was on point, very believable choices for so many characters, and the guy who played Lorne was perfect. I agree with Bill that the Jim Belushi guy was the one character that was a miss. It felt like his only knowledge of the actor was watching him in Animal House.
It was a lot of fun, good vibes, and lots of laughs. Parts of it felt unbelievable from a timeline perspective, which is a bit distracting but can be overlooked. It's interesting to re-watch some of the old skits the movie showed, and seeing how well they recreated those scenes and how good the actors were in mimicking the original cast. Here's the original Hard Hats skit, it's hard to believe that it was 50 years ago.