Even though the complex-number functionality of the 35s can be improved, I found it amusing that it has a short leg up on the TI calculators when it comes to trigonometric functions of complex numbers.
The 35s has no problem with cos(3i), while the TI84 gives "error data type" even in complex mode. You can get the same result using cosh(3) or (e^3+e^-3)/2.
I found that mildly interesting.
CHUCK