I'm just curious as to what motivates you to practice more of your sax? What motivates me is newer and harder music, and getting to the stage of perfecting it. If I don't have any new music to play and I have been playing the same pieces for hours it usually makes me stop, but if I just get a new piece of music, for example the Charlie Parker Omnibook I picked up today...
It makes me want to play every song till i have each note down cold, and I have nice tone on it too. I also like to improvise now that I'm getting better at it, so I practice that a lot, and knowing that eventually I'll be good at it is also something that motivates me to practice more.