MJ/MC is, without a doubt, in the top 3 pieces of software that I own. In terms of filling a certain niche (media playback and organization), it is unparalleled. Until I found MJ/MC, I was using WMP8 to organize my music. Ugh. Tagging was a pain, no organizational abilities, no views, etc... MJ/MC opened up a whole new world of possibilities, and as a result, I have actually gotten more interested in listening to and buying music!
Sure, you'll hear me whine as much as anybody else when I find a bug or have an idea for a feature request, but I see that as the nature of "neo-software-development". Software isn't developed in a vacuum and handed down to the users anymore. In the Internet Era, software is developed with the users' participation, and bug reports and feature requests are integral parts of the developer/user feedback mechanism.