I've shot maybe a hundred or more rolls with my ETRSI with the AEII, and it's performed great. I'll point the camera around and make sure I'm metering correctly, but usually it does a great job. In the colder months I keep the battery out of the camera if it's going to sit for a while, and I always keep an extra on hand just in case. I believe there is a battery check button to make sure there's still juice, but of course it could end up draining after a shot or two if the battery is ready to give up the ghost. I usually give my batteries a year or so before I replace them jus to be safe. The camera defaults to 1/500th if the power is exhausted. I've even checked my in-camera metering with an older Zeiss light meter I have and the two are almost always spot on so if you want to dump more bucks into film you could even spring for the non-metered prism if you had to. Depends on what you're shooting I guess.