I find myself using MMV(DragerXL) frequently on patients with a respiratory drive, but not ready for liberation from the vent(head injury, decreased LOC, COPD, etc.) My backup settings are usually around RR10, Vt 10ml/kg IBW, PEEP 8-12. I try not to use PSV unless needed to achieve a desired VT.. I find many patients appear more comfortable when you can eliminate the I Time. I set alarms; Ve=1-1.5L less than MMV backup, RR= Low 20's to not more than 32, high VT depending on patient, high PIP 30-40.
My hospital hasn't embraced APRV, so that isn't an option(YET), I'm working on it.

Thoughts, opinions

GJ