980TI is still great (esp OC'd). However, I would probably go for the 1070ti if same price. You get an extra couple of years of warranty (hopefully!), if not the card itself is newer.
At 1550core/8400mem, the 980ti is really close to a 1080 (I'm ~5% slower than a stock 1080 in benchmarks on my 980ti [those are my clocks on air, watercooling doesn't get me any higher]), however it consumes a TON of power (granted, I have mine at 1.281v). The 1070ti should OC a bit further, run cooler, and consume less power. You should read up on the matrix's voltage. IIRC, the Strix was rather locked down, not sure how much the PCBs differ.
What makes the 980ti look bad in recent reviews are the relatively low clock speeds (granted, not all hit >1450mhz, they should all hit a decent bit more than the stock boost clock of ~1200mhz).
I thought Pascal all kind of topped out at 2050-2100 regardless of cooling?