I've got a very plain Asus notebook (no Nvidia card, just Intel Graphics!) running Debian 8 and the situation is unacceptable atm. I didn't have to reboot for weeks in the past. At the moment I am lucky if my laptop doesn't freeze thanks to sleep/hibernate within 2 days.
I hate Gentoo with a passion. Being able to pick versions and set flags means that, between any two Gentoo installations, the difference is likely bigger than any two Ubuntu 16.04 installation.
I think it just creates more complexity for support scenarios.
I'd definitely not recommend it for "serious desktop use" unless you are a hardcore graybeard.
I don't agree with the support thing though. Most Gentoo users are knowledgeable; developers are always on irc/forums lending support; certain commands such as `emerge --info' make it easy to figure out what the state of the machine is regarding flags/masks.