What do you want from me? The most important element for you seems to be the outer 10% of the field of view, so why even bother with an HT?
I get it, you were not impressed - the brightness, sharpness, colour neutrality, great contrast and nice 3d effect - all are ignored if the outer 10% isn't sharp.
So that's what you like - not me - but that's why we have so many choices. My opinion of most current flat-field designs is a dull, flat and relatively lifeless image with weak contrast - but that's very personal and I realize many don't see it this way at all.