These are my very first impressions that popped in my mind immediately after having played with the calculator (which I got today). All settings were default (except that I changed the date and time to reflect local values).
1. Only 4 brightness levels (ON+ and ON- to change) seems a bit inadequate after having been spoiled with variable brightness from my iPhone.
2. Graphing is super fast. But no 3D grapher. This would be so easy to implement, why was it not built in?
3. The first 26 letters of the alphabet appear to be reserved variables?! =( Moreover, if they are built-in variables, then they, along with the standard matrix variables M0-M9 and several other types of variables, should NOT appear in the list of [b]user variables[/b]. My actual variables (that I created) are at the bottom of this giant list of system variables (I'm calling anything I did not create a system variable).
4. The connector cable has a tetrazoidal plug. However, the female end appears symmetrical. Given that my new cable plugs in very stiffly into the HP, it is hard to tell whether there really is stiffness or (in the worst case scenario) if I am plugging in the cable the wrong way (possibly causing damage to the female port).
5. The touchscreen is nice, but even with clean fingers I see too much of a "mess" when the screen is turned off. Fingerprints don't look pretty. I suppose it is a necessary evil.
6. The title of the home screen serves no real purpose in my opinion. Is it suppose to remind us what the last app used was? If I exit from the Advanced Graphing app to the home screen, my home screen is titled Advanced Graphing -- why? This makes little sense.
7. User-defined functions are always computed as decimal values, even if there were no "." used within the formula. For example, if I create a function called FXY defined as 1/390*(X^3*Y-X*Y^3) and then enter FXY(1,2) -- whether in the home screen or CAS mode -- I do not get the exact value.
8. The programming interface is poorly organized. There are so many blank soft-menus, and yet every programming command/feature is crammed into two tiny little menus!
9. Syntax error messages in programs (with the included line number) does not really help if: a) there is no menu option to go back into the program and have the cursor right at the error line and b) there is no actual line numbering within the program editor -- assuming (a) is not feasible.
Other than those annoyances, everything else seems peachy so far! I love the new design. The case, however, seems odd somehow. If you look at it from the underside, it just looks... like it doesn't fit well. When I hold the calc with the case on (covering the screen) and feel where the case borders the bottom of the calc, it feels as though the case were too big (even though I know it is not).
Edited: 23 Sept 2013, 10:00 p.m.