With a ton of hi res texture mods though which isn't typical.
The 4GB seems to have slower memory though, 7000mhz vs 8000mhz on the 8GB model is this something to worry about?
I see the 4GB model as being the 380 replacement and the 8GB with faster VRAM (if true) being the 380X replacement.
If performance is lower than or equal to 390 then AMD Polaris 10 is a dud IMHO. A die shrink card should be beating the previous gen card that is one tier above. It most certainly should not match the previous gen tier above card in price and perf.