Hey jpaul - just wanted to throw another vote in for "do it". I just came from a similar spot where I haven't really used my DAW in a while and had X3 Producer. Since I was able to see the additions over the past 2.5 years since I updated last, I found enough value in that for the lifetime update to be worthwhile. Now I look forward to the additional changes that will come down the road. A few things that stuck out for me:
TH3 Cakewalk Edition, Application themes (color), fixes and performance improvements, Melodyne improvements (that don't work for me at the moment due to a Celomony issue), the free Addictive Drums kits (even though I have a very capable Roland e-drum kit (in my profile pic), the additional synths like updated Lounge Lizard, the Analog Session synth, new things (I think) in the ProChannel, and others.
I have been playing around with the new version for the last week and I've not yet even touched a bunch of stuff - still trying to get back "into it".
Hope that helps push you down the road to new inspiration like it has me.