Yep, it's very slow. I do remember that. But it worked with one of the thousands of ANSI termcap entries, don't know which one. Likely MS just meant this thing as a server-to-server admin tool.
It does not follow the telnet definition. It is broken by design. I don't care if it is visually pleasing to an ANSI terminal. I care if I can script my interaction with it.