Breakout Boards and C-Compilers
I spent quite a while analyzing MicroElektronika's boards, since they happen to be from my hometown and are the only ones selling any serious development boards here.

My general impression is that they spent some energy trying to lock-in their buyers and make them spend money on some of their other products too. For example a lot of their development boards only have their own programmers which don't work with industry standard tools and instead ME's software needs to be used. Recently, they added pins for standard programmers on some of their boards, but from what I can see, the mikroBoards for UNI-DS aren't one of them, so that could be a problem if you want to seamlessly use other IDEs. You can always use their programmer to burn a hex file made by some other compiler.

Another interesting thing are their IDEs. They do look nice and have some interesting libraries, but on the other hand, they aren't that standard so some effort may be needed to port existing programs to them or from them. There's a nice chapter about that in the manual for the IDE, so you can get the gory details there. The features are definitely nice for someone who doesn't want to spend time on things such as making custom characters for LCDs, porting images for use on graphical displays, driving seven segment displays and so on.   The commenting system also seems interesting to me, since you can say put pinout images directly into the same window where code is or put links to websites and so on. In my opinion, it would be best to just download the IDE, if you haven't already, and make a few test programs to see how well it fits your needs and then compare it to MPLAB. The free version should work with programs smaller than 2kB. Unfortunately I can't provide more specific information on how good the compiler is, since I'm still considering if I should buy one of their boards.