Adobe has had some issues with a few of their updates which have caused some serious problems. On a percentage basis they haven't done that badly, considering they have issued dozens of upgrades and updates of Lr over the past ten years and only a few of those have caused serious issues. But those have been serious enough and obvious enough it makes users wonder where their quality control is and why they don't utilize a little larger beta test group.
Regarding this update, I will say I've been using it since it appeared on two different Macs, including raw processing of IQ3 100 files and printing with no issues. I haven't tried any pano merges yet to see if they broke that functionality (which I believe has happened twice before, once in Ps and once in both Ps and Lr). Maybe users who have tried that could chime in so those users wanting to "wait and see" have some feedback to help their decision as to when to apply the update.
Wonder if this will be the last release of Lr 2015 ...
anyway, here's my first image from my IQ3 100 processed in Lr. The use of the automask tool and brush adjustments gave me a better result than I achieved in C1. Not saying that's C1's fault, but I've just found my technique for this works so well in Lr and haven't figured out how to do it in C1 with the same simplicity and degree of success.
(if anyone cares, here's the details on the shot and post processing ... Phase One XF with 75-150 lens at 75mm, 1/80th at f/9, 6 shot focus stack using XF focus stacking tool, process in Lr 2015.9, output to tifs into Helicon Focus for merging, back to Ps as smart object with raw filter applied for final tweaking)