Actually no, they don't. Caliver have advised about 1,000 sold, so I would be surprised if '1000s' are using these rules. If you actually listened you would hear that I can use them;and have done so over a couple of years, but they could certainly benefit from a significant re-write. The fact that DBA and DBM are both mentioned at no 23 in the world's worst rulebook might give you a clue that many people do find them (DBMMs precursors admittedly), difficult to use. The constant debate on the DBMM list is evidence enough.