G-Sync isn't locking me into the nVidia ecosystem, the only thing really locking me in is nVidia's reliability at having release day ready drivers and SLI profiles. AMD has made outstanding hardware since the 79xx generation, they really just need to make sure it's hitting at full speed from the get go rather than 4-6 months after release. nVidia can't even claim better multicard scaling since the 290 generation came out, though what they can lay claim to is it almost always works and works right out of the gate, something AMD sometimes fumbles with. I'm envious of Crossfire scaling and of the long legs the hardware as of late seems to have, the previously mentioned things are all that prevent me from going back to AMD. With every AMD release I hope they crush it, it can only benefit us all.
Back to the gsync thing, I recently got a 2560x1440 gsync monitor after listening to all you guys go on and on about gsync/freesync and 1080p being a peasant resolution.....my general feeling is "meh". I guess the monitor is ok, but I haven't been wowed, not much of a leap from my Asus VG278H IMO. I guess the additional desktop real estate is nice, but I've been unimpressed in games. I previously said I was going to wait for a curved 34" 3440x1440 21:9 120Hz capable monitor before I upgraded but curiosity got the better of me, I should have waited...I think that's what it's going to take for me to go "wow".
To be clear, I am always saying people should go 4K Gsync/Freesync. I think it's good, but IMO, if I'm you, with 3 980Ti, I'm not getting a 2560x1440p monitor... That's still peasant resolution.
I would have honestly gone the AMH 409 in your position. Yes, no Gsync, but it's a large monitor, and you have 3 980Ti. You can handle the 4K glory.
Either way, 4K Gsync is what I would have said. I would have never expected you to be wowwed by 1440p gsync.....
I mean, in your position, I'd see if DSR + Gsync worked and how well it works. See, I like VSR a LOT, which is why I'm happy AMD has been a great value, because VSR quality is definitely preferable to me over DSR quality.
The whole point of Gsync is to be able to up the resolution you're playing at. Not the settings IMO. If you up the settings, the impact isn't so useful. It's really resolution that's the killer, and Gsync helps minimize that barrier and allows you to play at resolutions you wouldn't have been able to play at or render at before.
P10 in Crossfire will beat the 1070 SLI easily, and will be close to the 1080 SLI.
P10 Tri Fire will beat 1080 TRI SLI
Just like how I couldn't stand the Fury X because it was the same price as the 980Ti but slower (Even if faster in CF mode which is what I wanted anyway). I couldn't stand owning a 1080 TRISLI knowing the P10 TriFire would be faster. Which would lead me to not even wanting a 1080 because that's just gross that $2100 worth of GPU won't be able to be faster than $900 worth of GPU (P10 comes in at $300 tops, although at $300 I honestly will be slightly disappointed).