If you ever saw a LocalTalk network that had multiple zones, with dozens of systems per zone, you'd know the pure evil that it was... Even with a speed-booster (LocalTalk could be externally clocked at up to 2 Mbps, about 10x as fast as the "passive" serial port clock,) it was a pain in the @$$.

For less than a dozen systems, it was usually okay, but once you got above that, it became a nightmare.

Edit: The only thing worse was a NetBEUI network. /shudder