We moved in December, and I moved my 80 gallon 2 stage. I still haven't gotten mine hooked up, there is just so much to do (and getting the old house finished was a MAJOR undertaking). But I often curse not having it. That said, I do have a pancake one that has saved my bacon a few times. Even on the MTB, having it is nice to help set the beads on the tires, which is hard to do without compressed air, and I try to not use the CCO2 except for trailside flats. I also use it to get the foam style grips on and off the bars.
But overall, even though you don't use it often, you will miss it if you don't have it. If you had a big one like mine, I'd tell you to sell or leave it, and get a smaller one. I'd be more than happy with one the size of yours, but since I have painted a few cars, and I have a bead blaster, having the large one is nice.
In your case, you could probably have a larger pancake style one do the job, but since you already have the one you have, and it presumably is semi-portable, I don't see a reason to get rid of it.