Yes, I suppose for logging it works well enough. For data transfers, be it zmodem or IP over PPP, 115200 is not at all reliable, even 57600 is stretching it. 38400 works most of the time.
It depends on what else is going on. There were replacement serial.device where 115200 would work ok, especially on an a1200.
If you're using 16 colour highres screens on ECS or run a "blitter nasty" patch then you'll have more issues.
I don't think aros 68k is currently aimed at the unexpanded a500.