Flight Planning Software

I'm considering purchasing flight planning software, such as the
Jeppesen FliteStar or the RMS software or some other flight planning
software after I finish my flight training. I don't intend to have it
plan the route for me, but I do want the ability to change my mind "on
the fly" and see how that impacts my flight planning. I still prefer to
do the final planning by hand on paper with the software as a backup to
make sure I didn't make a large error in my calculations.

What have your experiences been with the different software? What did
you like and dislike about the software you used?

Thanks,

Chris