To add my .02,
 
 
  1.  When running a terminal connection using serial line and a DTC vs.
      a session through NS/VT, couple of things about the speed:
 
       - True, NS/VT session consumes some more resources on the hp3k
         (one more process).  Session start-up (getting the logon prompt
         and session built up) is slower than thru a DTC port.
 
       - Dataflow (painting screens - specifically block-mode stuff) is
         much faster through VT than DTC since DTC port is limited to max
         serial line speed, while NS/VT screens will come across LAN at
         10Mbits/sec rate.  If your DTC users have been working with
         serial line speeds of 19.2kbps or higher, the screen fill speed
         probably makes no difference (19.2k is enough to paint a whole
         screen in 1.0 seconds (24x80=1920 characters)) - the end users
         would not know the difference.
 
  2.  Block mode can and will work through telnet, it all depends on your
      specific set-up.
 
  ...there was a third thing I was going to mention... forgot... maybe later.
 
 
Cheers,
:-) Eero Laurila - HP CSY Networking lab, NS services & Network printing team.