The Z dwarf will induce fruiting earlier than Colt but won't likely get tall enough to shade a house. I'm holding my cherries on Z easily to 6ft and could go even smaller.

Are you doing much pruning to hold at 6 feet or is that about where they want to be?

A lot depends on growing conditions. You could probably get them to 10-12ft but it could be 8-16ft as well. No I'm not pruning much. One is pretty vigorous but most are puny.

I am inland San Diego with heavy DG soil. I have two four year old cherry trees on colt. I keep mine around eight feet with a single light pruning in the summer.

The hot dry summer and heavy soil keeps them in check. Not much growth occurs after June. Colt may get to 20-30 feet under the right conditions. No way they would get that big in my yard even without pruning.

Mine haven't been very precocious. This was the first year they set more than a few fruit. Maybe a 100 or so.