I run m0n0 in hotels as well. One problem with that many users is that you will hit the state limit. With so many people using p2p, you can bang into it with only 100 users. Also, the DHCP tables take memory, so you could be hitting a wall there as well. I would recommend several boxes with geographic separation.
And to answer you question, there is no hard limit, but when the memory is full, it is full.
Thanks for the info, I did have a technical question directed at Lee (not trying to hijack this topic), but does the RAM disk expand with the RAM the system has? I know you need at least 64MB of RAM for 1.2X release.
Does it benefit DHCP to have 512MB of RAM or more for more leases or is the RAM disk set at a hard limit regardless of the available RAM?