A lot depends on the relationship between the quantitative and qualitative data. In particular, when programs such as these say that they can be used for mixed methods, they usually are referring to coding open-ended questions from surveys, and then merging that coding with the original quantitative data. In that case, I suggest you look at the relevant online tutorials for each program, and see which one is easiest for you to follow.
Alternatively, if you have qualitative data from in-depth interviews that are not matched to quantitative data from a specific set of participants, then all of qualitative data analysis programs will do pretty much the same thing.
I think it depends on your utility and understanding towards the software that you are comfortable with. Many feel that Nvivo is easy to use but others might have a good command on Maxqda.