Summary: This one is my favorite so far. I have bought several. The calculator is very easy to use, has lots of memory, easy to program, and provides marked improvement in the area of complex number operations compared to the hp 32sii. As a EE I really appreciate this. The dedicated "i" key is a dream come true for an Electrical Engineering type like myself. My only complaint has to do with keyboard quality in terms of missed keystrokes on some units.
Summary: The keys on this calculator are horrible and start to malfunction within 4 months of owning it. They require too much pressure and do not hold up to constant use. I cannot rely of the results that I get. I have to double check (sometimes triple check ) my results. The keys are too hard and only respond if pressed very hard. I do like the layout and the appearance of it - I only wish that it worked better.
Summary: RPN calculators are hard to come by any more, but this one is just perfect. I actually am replacing my HP50g (~$150) with this one. For one, the 50g died after only 5 years and I didn't want to spend another $150 to replace it for the same thing to happen again. Hopefully this one lasts a lot longer. My TI's from H.S. still work 15 years later. But since then I have grown accustomed to RPN and don't want to go back.
Summary: I am a mechanical engineer and had used a HP20 for the past 18 years or so and loved it. When it passed away, I bought the HP35S thinking it would be probably better. I loved it until I tried to do the most basic thing. I never drank the cool-aid regarding RPN and have managed to live productively for 53 years using algebraic entry. The HP35S offers both but that is the rub. In algebraic mode, the P.O.S. can't do the simple task of adding say 3 percent to 4 x 6.
Summary: I have been using a hp 32s rpn calculator for 22 years. Now I am stuck running this (35s) replacement, and it is a nightmare. Some genius desided to move all the buttons around, and worse yet the 35s no longer has the polar/recatngular convertion funtion that I used on a daily basis.
Summary: I have 2 hp33s that I use everyday to help day to day land surveying. I used them so much the buttons started falling off. I then bought this hp35s which was the replacement. What a waste of money! It doesn't have the right functions to calculate and store traverses like the hp33. Also, the ALG mode doesn't flow. It is now a paperwieght and probably going to be a frustration target.
Summary: Very good scientific calculator. RPN mode helps make calculations quickly without extra keystrokes. Very good and sensitive keypad and easy to read high contrast display. Used in the calculations instead of daily model HP 50G.
Summary: Easy to use if. Direct switch with only a few changes from the older 15c RPN units. It is just hard to see the display. Especially seeing the difference between commas and decimal point is hard.