Well, it really is a great design. I bought one just recently because of its low price. Then a co-worker bought it off me 'cause he liked it so much. So I bought another couple!
Its only problem is its being algebraic.
20s is in some ways nicer than my favorite 32sii, for instance, the "load" feature--being able to download useful programs from permanent memory to the program space is really great--if you need to do a variety of tasks with a small, cheap) calculator (without lots of memory), and happen to need to do curve-fitting one day, and complex numbers another time, etc it is actually a superior machine to the 32sii, because the "overhead" required to key in the (functionally equivalent) programs on the 32sii is time-consuming. But if you are at your desk, curve-fitting is automatically an spreadsheet task.....
The lack of menus is also nice--for instance, getting statistics results is only 2 keystroke, rather than 3 (32sii requires going to the menu).
And the segmented display is GREAT in low-light.
The fact that it is a keystoke programmable ALGEBRAIC, is quite facsinating.
However, being a total RPN thinker, I find it cumbersome and error-prone for involved calculations, and the programs I have concocted myself require more lines, and more de-bugging than is the case with the 32sii -- but the latter is entirely due to my RPN preference.
But the end-game is already here as far as calculators go. Except for really cheap (say, less than $40 or so) there is just no reason to build powerful calculators:
If you buy a handspring, or a palm, or a Clie etc, you can load ALL SORTS of very good RPN machines (including the 48g series--the EMU48 or a similar em has been ported) right on--and there is GOBS of memory. And it is only a matter of (not very much) time before the high-powered $250+ machines with nice (really!) built-in keyboards (they click like an HP) are down to the $100 level.
the world is really changing fast......
