For me, I was alway attracted to the lower TDP of the Nvidia cards. I hadn't used any AMD/ATI cards in a long time and back when I did, those cards ran HOT. VERY, VERY HOT!! All that heat caused premature failures for me.
However, with my current Vega 56, after replacing the stock thermal compound with liquid metal and doing a little tweaking, the heat has been very manageable. I am now able to keep the fan speeds low enough that I can't tell the difference audibly between when my system is asleep or awake when doing simple things like surfing or watching some YouTube. I have been extremely impressed with how well this Vega 56 has been running.