FWIW, here is an in-room response of the GRS NEO8 "wide" flush mounted and center offset on a 12" flat baffle with a high pass XO. The plots are with (blue) and without (green) High/Low Shelves.
With the wing version, I get 2 bumps in the middle and 1 on each end.
With the flat baffle, 1 of the bumps in the middle goes away on its own and loses some low end.
With 4 High/Low Shelves (no PEQs), I get +/- 1dB (blue) on the flat baffle.
THD looks better on the GRS NEO10 plots posted above than what I see with the NEO8.