I think Pesterquest's overall quality is higher than friendsim's. There's no routes I think are outright unenjoyable whereas there's a few friendsim routes that I personally really don't like. The plot is very fanservice-y but it also goes in some interesting meta directions and if you enjoyed MSPAR as a character then there's a lot for you. Like Friendsim the quality varies pretty wildly from route to route. Personally I think Kanaya's and Terezi's are the weakest, while Nepeta's, Roxy's, Dirk's, Karkat's.... well, I like a lot of them lol. But yeah, your opinion may vary.

And as others have said, you should be caught up on the Epilogues. HS2 doesn't matter so much, and Beyond Canon I don't think has had any references to Pesterquest so far.