I'll give you the ones I've seen and liked.
Emporia State is playing lights out this year, and they have a very nice facility. My son's team was there early in the year, so the field conditions weren't the best (and the wind was blowing 30 mph) but was a nice set up.
Central Missouri State or it might have changed its name, has very nice facilities and an excellent post season record in the past decade.
Wayne State (Nebraska) and Winona State (MN) have also been in the postseason recently. Haven't been to these places yet.
SIU-E complex is very nice, but they are in the process of moving to DI, I think this was last official DII year.
Southern Indiana has a nice field, but not much else in facilities right there.
Take it for what it is worth. Just my opinions.