CASIO fx-991CW

[Dave Britten]

I agree with pretty much all the sentiments in this thread so far, but interestingly, my preference is slightly for the CW. There are a few very specific reasons and improvements that might drive you this way:

- The spreadsheet is much more viable now that you can set the auto-power-off to 60 minutes, and you can switch modes without losing your data (the spreadsheet workflow is a bit like working out a lengthy problem spatially on a piece of notebook paper, but you can go back and update your inputs or intermediate calculations without redoing all the subsequent steps by hand). It's also faster, and the page up/down keys make navigating the sheet quicker.
- Similarly, statistics mode doesn't throw away your data when you switch modes or power off. It's actually pretty difficult to inadvertently lose your data now, making the CW a realistic option for recording observations over a period of hours or even days.
- This is largely personal preference, but the feel of the CW keyboard seems slightly better to me. Not that there's anything particularly wrong with the EX, but I like the feel, spacing, and size of the keys on the CW just a little bit more.

There are some other niceties, like being able to define and use f(x) and g(x) not just in table mode (you can save even more space in spreadsheets by using these), but those three bullet points are the main differentiators in my mind. If those don't matter to you, stick with the EX. There are, unfortunately, a lot more reasons to not switch to the CW than there are to switch:

- Heavy users of the ENG keys will have to spend a LOT of time in the Format menu, and entering engineering symbols from the catalog menu is absolutely not worth the bother vs. just keying in numeric exponents. If you mainly only use engineering symbol output and don't rely on use of the symbols for input, or use of the ENG keys, you might still be okay here.
- DMS entry fares a little better, but you still have to press Shift to input the DMS separators, and displaying DMS is another trip to the Format menu.
- Converting results between fractions and decimals also requires the Format menu (I'm seeing a pattern here).
- Base-N mode is a lot less convenient, as you have to press Shift to enter A-F in hex mode, and you have to cycle through all the bases with the Format key (at least it's not a menu) instead of having four keys to directly choose a base. Fine for a one-off problem now and then, awful if you're a microcontroller firmware developer.
- Unit conversions, while not all that great on the EX to begin with, take more keystrokes here for digging into the menus.
- The CALC feature is totally gone, though the spreadsheet is potentially a much more powerful alternative, with the downside of taking slightly more effort to set up the problem. Personally, I never used CALC, but I know some swear by it.
- Multi-statement (the colon) is totally gone.
- No Shift-Solve from the main Calculation mode; you have to go to Equation mode and pick Solver, then type in your equation.

For the minority where the positives outweigh the negatives, the CW is worth considering if you want better statistics, and a $20 spreadsheet workflow in your pocket. For everyone else, I'm sure it will be decades before having to worry about the EX becoming difficult to find.