Thanks. The only Mac-only competition I know of is Cartographica, which is $500 vs $40 for Magic Maps.
It's mostly Objective-C. The core map-projection library is C and OpenCL, which I had a lot of fun with! I open-sourced that library (ProjCL) a while back: https://github.com/evanmiller/ProjCL
What are most customers revolting about? Problems with the Yosemite? They want it on another platform, like web or iOS?
It's a real elegant looking app, better visual design than your competitor in my opinion (although I'm sure lots of work has gone into that app, as well).
Bugs (including, but not limited to Yosemite) and some significant UX issues. One marketing problem I have is that although it's better designed than the competition, in practice it's not quite as intuitive as it looks. I characterized a "revolt", but in reality there are two camps of users:
* People who come from traditional GIS, who love it (except for the bugs). These are the revolters.
* People who come from MapPoint, who think they're going to love it but find some things confusing and give up. These people were always discontented with the software at some level.
The frustration from the latter group stems a few unintuitive workflows in the software (e.g. how data gets imported and linked), some of which are due to design flaws in the data model IMHO. So although the software looks good in screenshots, and many people get a lot of value out of it, Magic Maps needs some work beyond basic bug-fixing to be a "5-star app" that pleases everyone.
It's mostly Objective-C. The core map-projection library is C and OpenCL, which I had a lot of fun with! I open-sourced that library (ProjCL) a while back: https://github.com/evanmiller/ProjCL