It's a smaller monitor; what did you expect?
The touch buttons seem fine for me. I'm not sure if some aren't as reactive as they should be, or if it's down to some people not liking the force required to get them to respond (which isn't a lot, really; you'd probably be using more to press a physical button anyway). Really light (and I mean really light) taps might not register, but the rest do for me.
Edit: I just checked and noticed that the HP 2711x is a 1920 x 1080 monitor, not a 2560 x 1440 like I first thought. In that case, yes, it's smaller, but it'll be sharper and have more resolution. If you prefer size, why'd you go down?
I'm surprised it wasn't about the AG coating (that's one of my complaints) or response (of the panel itself) or colors or something though. Maybe the colors look off because it has the tinting issue? Maybe the wide gamut and AG aren't making the colors and overall look as good as you expected? Some people don't like these things and a TN panels works fine for them. If that's the case, stick with your HP and enjoy it; you'll be far happier. That's what matters.
What year/revision is it (there's a tab that slides out near the card reader and USB ports with the revision, date, serial number, place of assembly, and some other information).
How used is it? You can check the service menu to find out. To do so, turn the monitor off. Hold the second and and forth buttons, and leave the first, third, and fifth uncovered. Turn the monitor on. When all the LEDs light up, press the first (top) button and it should show, showing the backlight hours and other stuff. This'll tell you how used it's been. Once you're done, hit that same button to close out the service menu. You'll want to turn it off and then on again afterwards.