My experience has been similar to many others who are very satisfied with the NEO 112-II. I prefer my Mesa and Berg gear, but for modular convenience with outstanding performance you'd be hard pressed to find a better value in my mind. I mostly use them in situations where space is tight and/or there is a risk that they could be damaged (bad weather, rowdy events where the band is close to the s crowd, etc.) - if I need to replace them they always seem to be on sale somewhere.
The GK MB heads (especially the MB500) work well with them, but for me they seem to sound best when I use them with the Mesa Carbine M3. I know that may sound like an odd pairing, but I like it.