I've had a couple of both the Rift and Vive since they came out - the Rift is just superior in all cockpit games, both driving and flight. If you're into cocktail party type standing/room shooter type games, or some of the other gimmicky (to me) type of VR games, the Vive is great to show off in that setting. The controllers are nice, the standing/room experience is interesting (for a time), and non serious PC gamers will appreciate it more than the sit down Rift experience. Yes I realize there are controllers and extra sensors/software available for the Rift now too, but it's sort of the Vive in reverse in that context IMO.
If you can only afford one, and you are planning on using it for sims/driving, the Rift is hands down the best option. It just works better, the experience is better, and every developer in the sim community will tell you that getting the Rift to work with their product has been better than HTC's Vive.
I sold one of our Vives as it was just sitting unused, while both Rift's the neices and nephews fight over (mainly for Elite Dangerous but other games too), and just one regular users of our PC gaming array wants to use the Vive regularly, and that's for Onward (standing FPS military sim game, which now supports the Rift too at last).