IMO the 2 things you need to look at are memory type and cooling setup. The memory type will give you an idea of stability and overclockability while the cooling setup and be important depending on where you are going to run the cards and what ambient temps they will be dealing with. All that information can be found on these forums if you search around a bit.
Thank you for your reply! Yes I was considering the same parameter when I was looking for some RX.
About the cooling system, points goes to the Palit from what I've read in the forum. Noone have mentioned the Armor and for this reason I wanted to ask for some benchmark of the two cards.
I actually have no idea about the memory type on the gtx. I have to investigate a little bit more.