I don't drool over 'fast runs' as such. I admire the player's technique but as far as I'm concerned, 'fast runs' are the domain of the piano player. Also, fast runs just for the sake of fast runs isn't necessarily musical. Like any other playing technique, you use what the song calls for. Some of the greatest and most memorable jazz organ performances don't feature 'fast runs', just tons of feelings and emotions. If you're trying to impress someone with your pianistic skills, then arpeggios are great, but it is only one of a gazillion 'tools' one can employ to capture the essence of a song.

chas