You're right, Drew. Beertools Pro keeps track and subtracts from your inventory.
I've used Beer Alchemy, BeerSmith, and Beertools Pro. BTP is the one that I ended up buying. For me, it was all about the interface. There's so much functionality in it that I'm barely scraping the surface. Bobby M from HBT has a bunch of videos on youtube about the different features that are really handy.
Josh, when's the last time you updated your copy? I know they added Carastan back in July. If you post on their message board, they're really good about adding stuff people request.
On Tap: Amber Ale, Pumpkin Ale, Rye IPA, Wee Heavy, Apfelwein
Kegged: Barleywine, RIS, JD Barrel Barleywine, Bourbon Oaked Porter, Belgian Brown