With complex numbers in RPN mode, it is kind of confusing remembering every time which of the numbers of your stack corresponds to the imaginary part. The algebraic mode shows clearly the two parts (even with a marked "i"). I'm an RPN user (10 years with my hp48gx...I know, it is a luxury that can't be compared...but....)but certainly for operations with complex numbers I'll switch to ALG.

These are also other things that I expected from a just released HP calculator:

1) If they handle operations with complex numbers, why I can't see complex numbers as a result of SQRT(-1) or Arcsin(-5)?

2) If the 15c could handle vector and matrix operations, why the 33c lacks of that? I know that you can program 3*3 matrix inverse or determinant at most but labels are really few for 32k, and the variables also. The basic programs that the manual shows uses most of the labels for things that the calculator should have "in-build": linear equation solver, vector operations (dot, cross, polar to rect and rect to polar), simple matrix operations (inverse, determinant)

3) Casio "simpler and cheaper" calculators have matrix and vector capabilities. Of course they are not the RPN realm but they make the job (see casio fx-991ms).