Honestly, why do people even go for monitors with HDR 400, the spec does not have zone brightness, only HDR 600 and up do. Without zone brightness what is the point? The only thing I've heard about HDR 400 is that it is better than nothing, but is that worth this kind of premium?
While this may be a beautiful screen for gaming, the setups that can even power it at rates exceeding what lower cost screens can achieve are barely measured in single digit percentages. I suspect the market for these things is horrendously small, as in a minuscule percent of an already tiny percent of gamers.
I bought this monitor a few weeks ago directly from acer thanks to a promotion where I managed to get a decent discount. It is probably the best monitor I have ever owned and the HDR effect seems pretty decent, while standard range looks phenomenal and gsync works brilliantly. I can’t really fault it. I’ve read a few complaints online about 400 nit HDR, all I can say to them is this is a 27 inch monitor, designed to be used at close range than say a 60 inch tv made to be viewed from a distance, in that case I would agree 400 nits is too low.
IMHO, 27-inch 4K gaming monitors are pointless due to the pixel density and normal viewing distance of 2-3 feet. I've seen 27-inch 4K and 27-inch QHD (2560 x 1440) monitors side-by-side, and there really isn't much of a difference. As an owner of a 32-inch 4K gaming monitor, I know that's the sweet spot for the pixel density and viewing distance. I'm just have to wait for the 32-inch version of these monitors to be released later.