"Would you guys recommend Assetta Corsa over Project Cars for VR?"
Yes and no.
Assetto Corsa's VR implementation, performance-wise, is fantastic. Runs like a dream. Be sure to download the Natural graphics mod filters and disable crepuscular rays and heat haze or else it'll look extremely overexposed.
However, Assetto Corsa barely qualifies as having any real "game" structure to it. If you're not interested in just running hot laps, simple AI races with a limited sense of progression, or going online/playing in a league, you may find it boring. Also, Assetto Corsa doesn't have a VR UI, so you're going to be taking off the headset before and after every race. Annoying as shit.
Project Cars runs like shit. The framerate is all over the place, for no reason. You can finagle a semi-reliable framerate by turning on "always-on Reprojection," disabling Async Reprojection, and turning just about all settings (especially Shadows) off or low.
However, Project Cars does have an actual game structure. Playing through championships and leagues, getting offers to drive at other teams in faster cars, etc. And it has a fully functioning VR UI, so you never have to take off the headset until you're finished playing
Assetto Corsa also has better physics and handling than Project Cars. And mod support.
You'll have to decide which flaws are the bigger problem for you. Project Cars has a demo called Pagani Edition if you want to give it a try.