For 'grab and go' you could try:
- Puting one of your refractors on a better AZ mount - light and quick to set up, but limited aperture. (I hear the Explore Scientitic Twilight I is good, but I have not tried it).
- Considering the Nexstar SE8 - larger aperture but expensive.
Either may still be a little unstable under windy conditions, but might not be such a problem from an apartment balcony.
Another option would be to work out some way of putting what you have on wheels, and/or protecting what you have from the elements so that you can have it permanently set up on the balcony.
I suspect that once you have owned a 10 inch aperture telescope, you will always perfer the larger aperture option for visual astronomy.