I've got more than it's fair share of hours on a stock incand. bulb for my 3c, my father has had the same bulb for repair/power outage use for several years now on his 3d.
Keep in mind it's not on constantly, lol, but for fixing water leaks it's a nice choice. I think Mags are supposed to take a beating anyways, I kinda have three that have been through some rough times and drops and are still on the same stock bulb.
We use sometimes the el cheapo batteries you find on sale, but we've not even had trouble when the extremely cheap ones begin to corrode from moisture.
While i'm not exactly sure of the voltage compared from the cheap to the premium batteries, if the bulb life has been compromised a lot we have not been able to tell so far. Good thing is we still keep the spare in the tailspring well. Yet another good thing about Mags!