Agree with this, I sold my 970 and picked up a reference 780 for a great price. At stock it barely boosted to 1000mhz but I OC'd it to 1200mhz and it's benching better numbers than my 970 was. It's a beast with an overclock.
I find this hard to believe, in a literal sense. The 780 OC benchmarks here were used as a reference point against a stock 390 (970). Both of those cards overclock, especially the 970. Since per the benches provided, even a max overclocked 780 couldn't even match a stock 390, trailing it by 5-13%, and considering that 390 can overclock 15% (970 can overclock 15-23%), there will still be a 15-25% gap between a max overclocked 780 and a max overclocked 390/970 at 1440P. For $30-40 out of pocket, if he locked in a $190-200 resale on his 780, another $30-50 to get a 970 with AAA games or a 390 seems like a solid option.
Computerbase has a stock 390 outperforming the 780 by 24%, which suggests to me that 780 would need to be almost max overclocked just to even come close to a stock 390, which seems to be the case per the benches in this thread. But then you still have 3GB of VRAM vs. 3.5 on 970 and 8GB on the 390, and probably the worst possible driver optimizations and DX12 performance in 2016 games among Kepler, Maxwell and GCN architectures.
I guess it just depends on what games the OP will play and how long he wants to keep the card. Also, getting a free Assassin's Creed Syndicate game + 2-3 year warranty on a new card and MSI Gaming 390 or MSI Gaming 970 turn off their fans at low GPU load (quiet) are nice bonuses.