Cheers, guys.
So, my experience with the new update hasn't been that perfect, but it's ok.
Isengard is installed, 15.2, no question about it.

I've had to perform a factory reset and reinstall everything (addons, librarys, whatever).
Seems a bit laggy to me, much more than 14.1, but I'll give it some time. Fanart displays very slowly at first, but once it's in the cache, it's ok. Some addons don't work like they used to, but that's because you may still have the Helix version of those. Keep them updated and you'll be fine.

To my discontent, IPTV Simple PVR client is not working any more. Addon cannot be loaded. I've perfomed 2 more resets, uninstalled and installed it again and it's still not working. I've ran out of ideas...

Appart from that, I'll keep you posted for any other issues I may encounter.
Regards,
Art