Just to chime in here a bit regarding the Index:
The headset itself is fine, meaning if you have the room setup done you can play games no problem (assuming the games play nice with Proton, most do but I've seen a few hiccups here and there).
What is not fine is SteamVR. If you are unlucky the App will not really work with your PC out of the box, in which case you'll have to play around to get it working, switching to and from Beta branches.
Only real problems exist with the Lighthouses, you'll need a Script to put those into and out of Standby mode and updating their Firmware via Bluetooth does not work.