The way things are going and have gone these last 6 months with AMD, I'm just about to jump ship I think even with owning a freesync monitor. It all depends on how the 390x is launched and how they go about looking after their customers in that time frame. But, I've just about had enough with the company, its pretty much sunk and doesn't instil me with any confidence any more. I'm currently using the screen without freesync due to crossfire and my cards and its incredible without it....so jumping to Nvidia is no biggie, will just get a couple 980tis and run it at 144fps.
I loved using ATI/AMD cards back when i didn't work and they offered the best price/performance ratio on single cards and i always saw Nvidia as the overpriced option (which they still are but i can afford it these days), Then i bought a 4870x2/5970/2x 6950s and the ammount of issues i had with crossfire and driver issues in general were a joke (also waiting for 5+ months for a driver fix which by that time i stopped playing the game).
Then i moved to Nvidia and never looked back.
AMD lost a willing customer due to terrible software and im scared to ever go back to them and spend my hard earned cash.