Unlike the RPL series, they don't integrate with the rest of the calculator. And unlike RPN calcs like the 41 and 42, you can't program in RPN which many people

Unlike the RPL series, they don't integrate with the rest of the calculator. And unlike RPN calcs like the 41 and 42, you can't program in RPN which many people find very easy to do. TI's a fine calculator... for a middle school student.