I sent my Rift S back for refund as it just wouldn't 'play nice' - flashes, wouldn't start up without multiple restarts of the software or reboots of the PC. Positively, the sound was great and apart from the rabbit right controller issue (I ended up with 24!) no other controller issues.
Reading here of the latest software update I bravely went out and bought another this morning. This was a May build.
No problems installing (allowing a restart after firmware updates) go through the tutorial again then off to play.
A mess around in home, pick up all the Gift Packs, same odd behaviour if you grab the boxes too quickly, but otherwise pretty good. Fire up Fallout 4, play for an hour before taking HMD off as it is a bit warm here today...
No flashes, perfectly behaved controllers, good fun had by me.
Now, the odd bit - I may be kidding myself but clarity seems much better than the first S, brighter colours, good blacks, sound is fine.
I'm impressed, shame I'll have to wait for indoors to cool down a little to bury myself in Elite: Dangerous again 🙂