why prime has two modes? RPN and CAS?

[lemontea]

(05-03-2014 08:08 AM)Joe Horn Wrote:  OPINION: If you want and/or need to program in RPN, the Prime is not for you. However, if you only need RPN for keyboard calculations (which is where RPN really shines), and can program the Prime in PPL (which is MUCH easier than programming in RPN!), then Prime MIGHT be a good match for you.

Thanks... Joe you are almost on the verge of convincing me to get the Prime... almost, not just quite yet... :-)