I have a Vive and have tried VR porn. There's not a lot of say. You get some pretty bad uncanny valley issues and having a first person view of porn is weird and unatural and frankly unsexy. Porn that 'happens to you' doesn't really work.

I don't think porn VR is the killer app people think it is. Perhaps in a few generations especially in conjunction with tele-dildos or robot sex dolls or somesuch, but that's a lot to ask when ordinary 2D photos and videos get the blood flowing with much less hassle.