In terms of performance (which you didn't ask about, but still...), a single
Vax <-> 370 connection can run from 12 to 20 kBytes/second. This isn't too
swift, given that a Vax <-> Vax connection can run about 50-80 kBytes/second.
However, in the Vax <-> 370 case, the numbers appear to be additive; thus
two Vax <-> 370 connections (two Vaxen, one 370 = 3081) seems to run about
twice as fast as one, three connections run three times as fast, etc.
The Spartacus people DO support 3270 emulation. They do the protocol
conversion in the 370, which allows you to run from, say, an IBM PC or
TOPS20, or whatever. This is a plus. The downsides are two: 1) every
character is echoed from the 370; and 2) the 370 needs to know "/etc/termcap"
information about every terminal that will connect to it. (please note:
I've never used the Spartacus boxes or software, so I am commenting
based on what I remember from reading and discussing.
The Spartacus people do have tn3270, and may be trying to support that
interface as well.
Hope this helps.
Greg Minshall