I bought BeerTools Pro and I'm currently trialing Beersmith. Overall, I like the tools Beersmith has better than BTP. I like the mashing schedules and the ability to create my own mash schedules (extended double decoction). Once I work out the Starter settings, I expect that will be cool as well. I'm sure BTP will come out, at some point, with a new version that catches up or surpasses Beersmith, but for now, Beersmith gets the nod from me.
Someone mentioned ProMash, but from everything I've heard, it's not being developed anymore. To me, that's a red flag.