Something I'd like to toss in the ring as well, albeit it be slight. Many people report a slightly better FOV when using a VR Cover from vrcover.com
Being closer to the lenses and all that. No actual numbers but apparently it's very noticeable.
For HTC, people are doing a 2017 GearVR lens swap to improve the "sweetspot".
Here's how I would choose:
The I have all the monies options:
If you wanted the best
today, it'll probably be the Vive Pro considering it'll be some time before you can order a Pimax 5k+ and have it on your doorstep in a a few days. At this point, it's months at best.
Here's the latest Pimax production update.
Production Progress Update 1106
Down from that I would probably go with the Samsung HMD Odyssey + *plus* which starts shipping in 2 weeks. Hear me out.
You get a Vive Pro screen with even less SDE (slightly more blur) and can combine it with Vive controllers and lighthouses for amazing tracking. The cool part is that it's super mobile if you want to take it to a friend's place. Instead of carrying around all the base stations, etc etc, just use internal tracking with the included controllers. Perfect for a Beats Saber party or whatever.
The downside is comfort. From what I've read, it tries to chew and eat your head.
HMD Odyssey+ - Windows Mixed Reality Headset HMD - XE800ZBA-HC1US | Samsung US
The I am poor people options:
Rift
Good;
Better software experience with slightly better SDE, those amazing ass touch controllers and a much better price. Pretty good 360 tracking with 3 sensors. Already included headphones and more practical headband.
Bad;
Tracking a bit worse than Vive in terms of play area size. Cables are short.
Vive
Good;
Even better 360 tracking. Future proofing- tracking puck, valve knuckles, official wireless, SteamVR 2.0 backwards compatibility and because SteamVR is more of an open platform, you can use your Vive tracking hardware with future headsets like the Odyssey.
Bad-
SDE worse than the Rift, bigger hit on older hardware, improved headband/headset is quite expensive. Lots of reports on controllers failing.
Pimax 4k
If you like watching movies *cough* and sit in a chair keyboard, mouse and gamepad VR, like Elite Dangerous, Subnortica and other simulation style games.
It's cheap, the resolution is great and the SDE is hardly noticeable.
Bad-
Options to get tracking is very limited. Ghosting.
Lenovo Explorrrerrer - Or other WMR devices.
Cheap. Decent tracking. Nice Resolution. Portable. Will kickstart your VR cud journey. I think of them as the Consoles of the VR world.
I don't need VR in my life now I can wait options:
Pimax 5k+ with their SteamVR Tracking 2.0 controllers and lighthouses.
Clarity is much better than the 8k, using the native resolution and all.
Awesome FOV.
Can drive it with existing hardware, sort of.
Pimax 8k X. The X will support native resolution input and won't make use of up scaling. So all the benefits of the 5k+, but with a higher res.
Can you say RGTRX3080Ti Titan Black XPpP Edition in Sli?
If you want to be more mainstream I guess you could wait for the Vive Pro bundle as well, not sure why you'd want that over the higher FOV sets though.