That's one thing I'm really happy about with ZRP-6.  I almost never used rs232 on our jobs that had an RP-6 in it because I couldn't justify the cost of a couple CM232s.  Now we've got two built-in 232 ports so I'll be using 232 every chance I get.  No extra cost, nothing extra to order, no little part that you thought you had in the truck but you actually didn't, etc...