I bought the iBrewMaster app for the iPhone first, and really liked it. The timers, the recipe management and other features are great. One thing that makes it stand out is the batch feature and how it will integrate with your calendar. The key workflow here is that there are "recipes" and there are "batches" which may be a slightly modified version of the recipe due to circumstances of the day etc.
Fast forward a batch or two and I decided to spring for the iBrewMaster mac app. Big disappointment so far. It is buggy, lacks polish and has strange implementations of some of the features (and missing features of the iPhone app). It seems like the iPhone app is the flagship product and will get the most attention so I'm considering the Mac app a $14.99 loss for now.
I downloaded the trial version of Beersmith 2 and, once I got the initial concepts, ended up liking it quite a lot. I was able to import some Norther Brewer recipes and the tools it has included (hydrometer conversions, scaling etc) are all top notch.
But there's a catch.... Since there's no batch feature, you can't track your batches separate from your recipes (I could technically you *could* but it would be a mess). The main thing I like about the batch feature in iBM is that you can track "actual" values over "estimated" for things like gravity and ABV. Overall, however, I like the Beersmith feature set over iBrewMaster's Mac app by a long stretch. If Beersmith supported batches (separate copies of recipes that have a few additional features), I'd be pretty happy.
For now, my workflow will be overkill until I settle on a clear toolset.
I will keep recipes and inventory in Beersmith2. I tried to export the recipe from BeerSmith 2 into iBrewMaster for iPhone but it messes up the mash steps and brewing instructions so in most cases it is easier to just transfer the recipe from Beersmith2 into iBrewMaster by hand once I have things the way I want it. That way I can rely on the timers in iBrewMaster while brewing since its much easier to keep my phone handy than a computer (and I don't have a printer).
To further complicate things, I keep meticulous notes of the entire process, day by day, in a per-batch text file on Dropbox. Once the batch is done and served, I'll just copy and paste those notes into the BeerSmith notes field.
What a pain huh? I wish I had an app that synced my recipes between devices, had batch support, had easy inventory management and worked flawlessly.... That may be a bridge too far for right now.