I've had other HPs (28C, 48SX, 48GX, 33S, 35S, 49G, 50G, Prime) but the 15C is the one I keep returning to, as anything more powerful really should be handled o

I've had other HPs (28C, 48SX, 48GX, 33S, 35S, 49G, 50G, Prime) but the 15C is the one I keep returning to, as anything more powerful really should be handled on a computer CAS like Mathics or Matlab-like environment like Octave instead.