I've been tracking OS X updates for quite a while, and this one ranks among the largest ever. Dumping the BOM file into a text file, and then opening it in BBEdit reveals a total of 16,915 changed files on my MacBook Pro. Despite that, things seem to be running very smoothly here after the update. I've been using the machine for a few hours now, and haven't noticed any problems--I wasn't having any before with this machine, so it's a good thing when an update doesn't have negative consequences. As always, though, your mileage may vary, so please, back up your key files before updating.