Re: Piano or sax?
My main instrument is the drums, but I play around with the alto sax and the piano.
Between the sax and piano, they inspire different improvisations. This could be the limits of my playing, but when I play the piano I tend to play more chords and rhythmic type melodies then a true melody line. The sax is all melody, and I improvise true melody lines not just a rhythm. The sax has the ability to sustain notes. Of course, an electronic keyboard also has sustained notes.
Yeah, you can understand more theory from the piano, but to have a real contrast to the drums and play melodies, the sax is the instrument.
I am not here just to keep the beat; I add color, timbre, and presence.