Yes, I would say there is enough value in upgrading if there is relevance that is for your environment. I upgraded our demo solution when it first came out, at 4.6 i could run a RDP session from home on my 1Mb with 128kbps of bandwidth, however i couldn't even establish a PCoIP connection. So i sat at home one day, working obviously, and thought I'll do the view 5 upgrade. Fairly painless as I have few users to notify and just with the default settings I could not only establish the session but also work happily on it.
The additional functionality, such as RTO integration, Session auto reconnect, Performance and Scalabilty etc make it viable. The question is, do you need to upgrade if users are happy with the current solution? are the updates relevant for your solution if so upgrade if not don't.
reagrds
Paul