Have you any experience with Pex MySQL running on a server network with 100-300 Users? Can it cause lag? I'm currently thinking about installing it, not sure yet. Are there any issues with using it? Thanks
It would definitely have performance increases compared to flatfile permissions storage. As long as the database is hosted locally on the same machine, there shouldn't be any issues with lag. I've managed a few networks in the past with ~100 players online simultaneously, and we used SQL for permissions. I wouldn't have even considered flatfile.
It would depend on the latency between the two machines. Ideally you would want both machines to be in the same datacenter and for the latency to be less than 20-30ms.