I and my organization have had reason to utilize various sizes of batteries in products that we have developed for our customers. We have tested a great number of brands, and have found the Energizer line to be the absolute best of the non-rechargeable alkaline batteries, bar none. This opinion includes the "other" "high end" batteries (with the copper.)If you need long-lasting batteries, I HIGHLY recommend Energizers.
I have dealt with MCM Electronics a number of times and have been more than satisfied.