I used RT a looong time ago around 1998 & 1999 and liked it, but OTRS,
compared to THEN features is superior. I haven't tried RT yet, although I
did start installing it and I know I gave up on RT once when trying to
install it but got OTRS up and running rather easily, so I can't say about
their new things.
I do know that there is a feature article this month in Linux journal, Linux
review or one of the Linux related mags that states that OTRS is used by one
national British ISP that pumps 20,000 tickets per DAY through it, and one
business that has around 2,000 CSR's using OTRS for customer support
services, both using MySQL as the database backend. I thought that was a
pretty good testament as well.
william