Sadly I had 4xR9-290s MSI Gaming 4G hitting crazy temps which left a bitter taste in my mouth.
I played around with a R9-290 Tri-X that could handle the heat better (57c at full load) and was a lot happier.
I prefer the plug-n-play option though with Nvidia, with little to no hassle on the software and bug side of things.
Will have to wait and get the Titan X to give a unbiased opinion. You never know if I would get ticked off.
Msi gaming though alright for single configs is not that good for multi with the heat being dumped in the case. I personally have not found Amd any less plug and play. The Titan-x will have to come down a lot in price for me as in principal even though I could buy it I could not give that money away on a single card. If it was 3 times as powerful as a 290 maybe but with the 390X coming soon I think it will be the card to go for. Maxwell seems to have lost it's advantage with the Titan-X as heat and power consumption is much higher compared to the 980 and fans have to be ramped up to compensate.