Nothingness: Game length in itself doesn't mean much. Many Anti-Backgammon games last over 200 or even 300 moves as well, yet there have been more Anti-Backgammon games than all the Espionage variant games combined.

I've only played a few Espionage games (not even enough to own any BKR). The main reason I don't play it is the BK is a turn based website, where games can easily take months or years to finish. This is fine if the board reveals all information needed to play the game - that is, history isn't important. This is not the case with any of Espionage variants, which makes me not to want to play it.