GA Callsigns

We were always taught to refer to ourselves on the radio with our full
callsigns until ATC refers to us with a shortened callsign (i.e. the last
three characters). However, I've noticed that the majority of the approach
controllers refer to most of the GA aircraft as "November" followed by their
numbers/letters. My question (to controllers in particular) is, do they
prefer us to refer to ourselves thereafter as "November xxxxxx" as well or
do they prefer us to keep with the "Cherokee/Cessna/Mooney..." moniker?

Minor point--I know. I just like to try and improve at least one thing
after each flight.

Marco