From what I "saw" during the benchmark test, "visually" 3880 is fast enough (barely). So, RX480 is not fast enough on Ultra -- but is more than fast enough on Extreme (my setup is nominally Extreme). Reports say that RX480 does even better in actual games -- we'll see.
Anyhow, if these numbers hold up when the official numbers become available, RX-480 at $229 is a good upgrade (by my standards) for 2x HD7979 (my games play well on a single HD7970). Odds of me buying RX480 for myself have improved. If I buy one for myself, I'd give my wife an HD7970 until the Vega comes out (then buy a Vega for myself and give her the RX480).
[EDIT] Another article indicates virtually no difference between the $199 and $229 RX-480s in the Ultra benchmark. On that basis, I would consider the $199 version. We'll see.
Last edited by Allen; 06/16/1603:34 AM. Reason: Added Info