just some advices about 2016.1
for Design NOT using petalinux, it is most likely is OK to upgrade to 2016.1 now, ODD release tend to be more "unstable" than EVEN releases, but 2016.1 has some nice new features:
GOOD NEWS: as per change notes, it should be possible to include plain VHDL files into IPI BD (we have not verified if or how good this works)
GOOD OLD NEWS: starting from 2015.4 already, labtools (aka chipscope) IP Cores are free with free webpack, so there is pretty much no difference between paid and free versions (only device support is different)