The monitor we are talking about hasn't even been released yet dude. We are hoping for September.
However, if you have the patience to read through the Philipps 40" 4K thread on this board.....
You will find a user in there who has was using the LG 34" 34uc97 (the curved 34" 3440 x 1440 IPS) and then picked up the 40" Philipps for comparison.
I was really interested in his thoughts, since I am using the exact same LG 34" and was considering going BIG 4K for gaming (was running 2 x 980s back then, am running 2 x Titan Xs now) and sent him a few PMs asking for comparison.
In his opinion, HANDS DOWN WINNER was the big ass 40" 4k Philipps (again, we are talking for gaming). He played some of the same titles as I do and is NOT a competitive online FPS guy (i.e. online BF4, CoD, etc) Instead, he enjoys PvE FPS (Far Cry 4, etc) and RTS and online MMO games. He loved the Philipps for this and said he would never go back to the "tiny" size of a 34" 3440 x 1440
He posted some side by side pics of the LG vs the 40" Philipps on his desktop. The Philipps IS HUGE and towers over the "tiny" LG. This reminds me of the time I bought the 27" Asus ROG PG278Q swift as a possible replacement to my 34" LG. I couldn't do it. The speed was nice, but after getting used to 34" / 3440 x 1440 the Swift literally felt like stepping down to 22" monitor from 2010 so I sold it. He felt the same way about the 34" LG. Once he got used to the size of 40" 4K, he couldn't go down to anything lower.
So I think you'll find its a case of what you are used to. Im used to 34" 3440 x 1440 and there is no way I would down grade to any 27" or anything at 2560 x 1440, including real gems like the 144hz 2560 x 1440 IPS models we have out there now. Nope, I cant do it; 27" is tiny for me now days. The only way I can go is UP. I would go to a 40" 4K once the pic quality is nice. Or I could go up in speed, keeping the same 34" 3440 x 1440 real-estate. Ideally, I would love to go up to a 75-120 hz 40" 4K and drop in a 3rd Titan X, but that display tech simply isn't going to show up for a LONG time. I cant downgrade to a TN panel ever, once you go IPS color you aren't going to accept TN colors ever again. So I would think if you got used to 40" 4K like he did, you would NOT be able to step down to this new upcoming Predator at 3440 x 1440 @ 75hz or even @ 100hz. Your perceived benefits from picking up 15hz or even 40 hz + g-sync vs what you give up, i.e. 4k res on a nice 40" screen, well, you just wouldn't be happy with it.
Anyway, find that guy in the thread and PM him, he will reply.
This is why they need to make a large G-Sync monitor. I can't live with a tiny ass screen anymore, and I can't live without variable refresh anymore.
These shitty display manufacturers are dropping the ball. It's absurd that there isn't a monitor for everyone.