I have an M32Q and I have no issues with it, no defects of any sort, the KVM is excellent and so very useful and having a Type-C connector with 'some (15w)' power delivery is very useful. I really can't fault it. It's fast, has good contrast for an IPS panel, it's well calibrated out of the box and is over all a good quality and subjectively pleasing display to use, speakers actually aren't terrible either if you need them just for Youtube or whatever, I wouldn't recommend them for gaming or listening to music but if you typically use headphones for these things and just want to not wear headphones for a bit they are good enough in my opinion that you can forgo separate speakers.
Although not directly related to this monitor, what I would say is I'm personally not actually sold on the 32" formfactor with 1440P resolution though, I do notice a loss in sharpness compared to a 27" monitor with the same resolution so a tighter pixel pitch, but that really depends what I am doing as to how noticeable that is and not having a 27" 1440P monitor right next to it to compare to would also reduce the effect of this, I've got an LG 27GN850 next to it and you can see it is sharper, but, such a configuration is also useful for showing how good the contrast is on the Innolux panel the Gigabyte uses compared to LG's nano IPS. On the other hand you get a more immersive experience when gaming on the M32Q as it's just much bigger. If you want a large format fast IPS panel, I recommend it. In a nutshell, I think the 32" 1440P in general works best for gaming but 27" 1440P is better for working with text.
Yes you can return one you are not happy with, first thing I do when I unbox a new monitor (this happens a lot as I have a bit of a 'habbit') after checking for physical damage is I run though a dead pixel and subpixel check on red, green, blue, black and white backgrounds and use the black background to check backlight bleed and panel uniformity too, if I'm not happy with all of those things it's going back. You can find a handy tool for these checks
here.