Awesome! I didn't think I'd use it as much as I do, but since I had it, all my packs have been cycled/tested and their capacity with date written on a sticker on the battery. That way, I can check it again at a later date to compare how the battery is doing (and/or pack quality).I did, but I must admit I've haven't used it yet. I do have one battery that has been misbehaving I think, so now I have a good reason to use it!
If you do something like I've done, either use a Sharpie on the pack itself (some PEC-12 will remove the marker) or put the sticker on the bottom END of the pack (door/latch side) so that it doesn't get stuck in the back!