I've had the same deliberations about the cali duster. I thought maybe on a car worth 30k, its useful and works well. But on a $80k m3, i'd prefer to minimize swirls marks in the clear coat. I like to drive a very very clean car, and wanted something to touch the car up with between washes.
im wondering if just a wash spraydown without soap would do the trick. (just bc its 25 here in NYC today)