>Indeed, my club has a rule that you don't refuel the aircraft after a flight, giving the next user more flexibility when it comes to choosing his (or her) load.<
This should only really apply to the touring aircraft of your club where there are indeed often W&B problems with high cabin/baggage loads.
The basic training aircraft should really be fuelled to a club-recommended level to reduce the possibility of condensation/water-contamination/ corrosion.
Thus it follows that a pre-flight fuel drain check is vital on the touring aircraft as well as regular checks on fuel filters by your engineers to check for corrosion debris.
