I use Ballistic for personal (set up in English units) and Ballistic AE for work (set up in metric units). It's a good general purpose tool. I like the user interface, which lets me see all the input parameters on one screen. It has a decent HUD interface too. The programmer frequently adds new features and updates the ammo library. I haven't been motivated to try anything else. Now I have a library of dozens of custom loads, so it would be painful to switch apps.
Ballistic has a cool target scoring routine that's unique. You take a photo of your target, drag the scale bar to calibrate the image, then drag a POI marker over each bullet hole. Ballistic then calculates the group stats for you. It takes a couple of minutes per target to set it up.