Probaby gonna get a ton of flak for this but...

[Steve Simpkin]

As John Keith mentioned. It is more of a personal preference to use RPN/RPL over algebraic/textbook entry. For many decades almost all HP calculators were RPN entry only so HP users became accustomed to and trusted using RPN to solve problems. At the beginning of handheld scientific calculators, there were were many clear advantages to using RPN over so-called algebraic entry. RPN very closely mimicked how you would solve problems using a pencil and paper (or slide rule) so it was somewhat easier for engineers and scientists to transition to using it. Most importantly it allowed you to work with arbitrary complex equations that could not easily be solved using algebraic calculators of the time. Remember TI's first real scientific calculator, the TI-50, didn't even have parenthesis keys let alone know about more then the most basic rules of operator precedence. There were many complex problems it could not solve without carefully determining the best way (order) to enter the problem, writing down intermediate answers and then manually typing them back in. Over the years there were many, many variations on algebraic entry calculators so you had to intimately know the "rules" of entering a problem on your specific model to get a correct answer on a complex equation. Even today with advanced textbook entry, entering a problem like 48/2(9+3) will get you different answers from different calculator models. RPN on the other hand has been very consistent over the decades, with only minor differences when RPL appeared in the late 1980's.

Over time, with the advancements in technology, the advantages of RPN are less important than they used to be but for those of us who grew up using HP calculators, most of us still prefer to use RPN/RPL entry. It is particularly good at solving quick exploratory problems where seeing the intermediate results is still important.

In conclusion, I'll leave you with this tidbit of knowledge to consider
Enter vs Equals