there are myriads of different environments and things that are available or not, or apps that you use or not, …
I’m not really sure what you are expecting. If you want to tune for better performance, you can use the support template to share your configuration if people have an input of that where they see a bottleneck.
If it is a single server system, with 300 users you might come to a limit for single-server setups (certainly depending on the server, usage, …). From some older docs, I think around 100 users they considered “safe” for a single server setup, however I cannot remember if that included talk, online office, …