I won't criticize anyone who wants to wait for Vega or Big Pascal or CF RX480. To each his/her own.
In my case, I bought the GTX 980TI SC to nearly replace my 2 R9 290s in CF which I still use in my 4790k rig. I had them and still use them. I wanted to get away from dual cards in CF/SLI to a single powerful card. Since I already had the GTX 980TI SC in my 5960x rig I decided to focus on my 4790k rig and get a single card.
Fury X was out and I decided to wait somewhat to see what Polaris/Pascal had in store.
AMD leaked some info in January about how good Polaris would be etc and I got juiced up to see a card. As typical Nvidia was VERY quiet, letting AMD "beat it to a pulp" over DX12 and Async Compute etc. Then BOOM out of the gate came the GTX 1080 followed shortly by the GTX 1070 (available today) and AMD? We think the RX480 will be available at the end of the month but the closest we came to hard info on it's power was that 2 RX480s in CF beat a single GTX 1080 in AOTS 62fps to 59fps. In contrast we've had TONS of GTX 1080 gaming reviews showing it out in the lead in almost every game.
You now couple that with reviews the past day or 2 showing the GTX 1070 being a decent card and the choice for me was easy.
No more "waiting for Vega". Don't want 2 RX480s for @$400 which "might" beat a single GTX 1080 especially since I don't want the CF/SLI issues.
Frankly, I bought a Zotac GTX 1080 FE since I already have an EK GTX 1080 full block BUT the GTX 1070 probably wouldn't be a bad choice either.