I've been monitoring the performance of the new dedicated linux server and things have been fine performance wise with smaller groups (10 players) however the game server only is utilizing one cpu core. Looking on google this seems to be a problem with the linux server version people suggest that the parameter -cpucount has no effect and I would agree with my own tests and this might explain again why there are alot more Windows based servers in the server list browser.
I wonder if any work is being done on the linux server to allow it to use more cpu cores? I will go ask on the Bohemia forums ;-)
Whilst I work out the cpu usage issues I've setup another game server (marked 2nd Server) this will feature either an alternative map (Zargabad at present) and will run beta versions of the Arma 2 OA Linux server software.