1060, 1070, 1080, same gaming performance between laptop vs desktop or no?
I'd say it's far more comparable than the 9 series' M cards. The laptop chips have the same specs as the desktop chips, but they're probably at a lower frequency, due to worse cooling. I'd say they perform negligibly different.
They won't turbo as much, as strong, or as long as the desktop variants, and they can't really be overclocked.
Outside of that they are identical generally
Normally it's 90% of desktop performance