I have to agree.
I actually purchased CMBB first, when I saw the Special Edition version on sale for $19.99. I hadn't really paid too much attention to the Combat Mission games before, as I was under the impression that they were "real-time strategy" games. While I suppose there's nothing wrong with RTS, it's not one of my favorite genres.
I bought CMBB anyway, due to the subject matter. I have some intrest in the Eastern Front, and thought the game would be an interesting diversion, if nothing else. Once I got it home and began reading the manual, I was stunned to find that the game was indeed a true wargame, not RTS. I was thrilled by the concept, having been a "traditional" wargamer for some 25 years. Finally, someone had gotten computer wargames right!
Well, naturally once I learned this I had to go find a copy of CMBO. Since I got it about a month ago, it's nearly all I play. Yes, someday I'll get CMAK, and someday I'll go back to CMBB, but for now, CMBO is my favorite wargame.