Google's advice was always emulation--the tests running on dozens of Dell servers were faster and more reliable at bug hunting than physical hardware. Obviously

Google's advice was always emulation--the tests running on dozens of Dell servers were faster and more reliable at bug hunting than physical hardware. Obviously there are limits, but the advice in 2013 was to prioritise automated tests in simulators instead of on real devices. Note the emphasis on automation, though -- you can totally expense that Tesla for the manual/acceptance testing ;-)