I've only glanced at SymbOS so far. Tried it once on my CPCplus and didn't get far, don't remember why.
So far I haven't added any additional memory to any of my machines, because I haven't had a need. But this online IRC thing is really intriguing, and I already have the M4 card.... and Bryce's USB mouse-port.
@Bryce! I think it's time to get myself that memory expansion you made room for back then.
Having the CPCplus, I can't help wonder if there's a cartridge version of SymbOS available. Would be awesome to have a cartridge version with the essentials, for extreme fast loading.
I have no knowledge about the technical aspects, so sorry if I'm fantasizing about the impossible.