As Adrian has already said each individual has to decide if the upgrade is worth it for themselves, no one else can really make that decision for you.
Look at the new features the upgrade gives you & how they may affect the work you currently do & also any new work that you might be able to do if you had the new features. That will help with your decision.
I run some software that is quite old because it does everything I need it to & none of the features added to newer versions would really benefit me, yes it would be nice to upgrade to have the latest version but for me with that software I can't justify the cost just for the luxury of being up to date
As far as my Vectric software is concerned then Yes the upgrade from V7.5 to V8 was not only worth it but I thought very very good value for money, V7.5 to V8 gave me the ability to machine 3D models directly & came with a lot of 3D models built in that I could use as Adrian has already said.
Just as importantly the step up from 32 bit to 64 bit for me was a big time saver in the work that I already did & knew it would also save me a lot of time with the 3D toolpathing that was also being introduced.
As Adrian has said, download the latest trial version & have a look for yourself, there have been some big changes since V7.5, not just new features but also additions/improvements to existing features which may be of benefit to you