YOANDY,
RX-VEGA is an excellent architecture with two main drawbacks. One is the power efficiency, and the second is the lack of software that will utilize the card well. (and the pricing too)... if we fast forward a year, RX-VEGA will do better relative to the current NVidia competition in some games...
I'm not necessarily recommending RX-VEGA but people should at least educate themselves a bit better. For example, if an Asus Strix RX-VEGA56 card cost the same as an Asus Strix GTX1070 I'd probably go with the VEGA56 card, but if it was a GTX1080 I'd need to think more carefully about it...
Problem is though that due to driver and game support issues, the RX-VEGA56 card is 75% the performance of a GTX1080 in some games and beats the GTX1080 slightly in others so it's all over the place whereas the GTX1080 is much more consistent... then there's the question of stability and smoothness which is hard to answer...
Anyway, AMD has a great architecture happening and since the core GCN architecture approach is in the XBOX ONE and PS4 game consoles we can expect code to optimize toward that more as time goes on (and NVidia's next GPU's to more closely approximate GCN as well primarily due to the console influence).