One problem with re-trimming a model for approach is when you forget to reset the trim for the next flight. I've seen more than one model get into trouble when the pilot forgot to retrim before take-off.

My Twist 60 is a prime example of retrimming a plane. As it burns off fuel the CG moves aft requiring trim changes during flight. When I fly a full tank out and dead stick I have added 5 clicks of down elevator trim. There have been a couple of times I taken off and found it way out of trim and remembered I neglected to reset the trim after I landed. [X(]

When I fly fullscale I always use the trim during all phases of flight. For models I trim the plane for cruise flight and dont' worry about it after that. The only change I would do for retrimming would be an elevator/flap couple using a computer mix if necessary - then its set once and not worried about. Otherwise I prefer to feel what the plane is doing.

Hogflyer