I have the following boards...
2 x MV1C - 1 in a cab and 1 in a JNX CMVS, both used regularly
2 x 4 slots - MV4FT & MV4FT2 - never use, would like to get rid of them
1 x MV1B - part of Irritating Maze kit
I like the MV1C design, though I will say the sound quality is slightly better on the larger boards. Not interesting in collecting board variants. There are probably 20+ different ones.