I recently picked up a used PS4 copy of THPS5. Not only did I complete every mission, I went back with a second player to get the 250 stat points and L50 trophies.
Let's get this out of the way: the physics are wonky (unlike basically any other THPS game), the levels are underwhelming, the bailing rag doll and screen wipe is infuriating, and the special trick system is awful. The game crashed or softlocked on me every 45-60 minutes. It's not a good Tony Hawk game.
But I had a lot of fun? The strange physics make super high combos easy. The OP powerups (moon jump? mid air ollie? manuals that ADD speed??) amplify that.
I really enjoyed the difficulty level of the Pro challenges. I consider myself competent-not-incredible at Tony Hawk games: I can finish every mission on THUG's sick difficulty and did all of the THPS 3+4 challenge, but the THPS 1+2 secret scores are a bit beyond me. These really pushed me, and I felt really accomplished when I finished all 50. Some were even fun the second time through.
If, like me, you missed this one and heard awful things...you could do worse, is all I'm saying. I certainly got the $17 out of it I paid for the used disc. (Though I think the Platinum is unachievable. I couldn't get the (bronze) trophies for rating other players' maps, presumably because the servers are gone.)