SVR4 upgrades

[mx!cacsc243 at csun.edu]

We just recently got a box running Sys V.3 where I work.  I am the sucker
who was drafted to sysadmin, so...

We are doing development for large embedded systems on this box.  The
maintenance contract we are buying is supposed to provide for free incremental
V.3.x releases, but if we want V.4, we gotta pay.  What are the advantages
of V.4?  Is it a true BSD/SysV combination?  What did they do about the
(IMVHO) screwed up BSD TTY driver (before you flame -- my opinions are
based on an early release of Ultrix running on an MVIII which WAS screwed up),
or are they using the SysV drivers?

Curiously

Scott