I'd go for the OM-2(n). No battery issues, and you don't even have to switch it on to get a correct auto exposure because the exposure metering is switched on by the mirror flipping up. The viewfinder meter is separate to the auto exposure. The electronics are no longer repairable but seem so reliable that this is really not an issue. OM-2s are cheap enough that if one goes wrong, it's probably cheaper to buy another!