'Negative' flaps would be spoilers. I'm not very good remembering all these terms.
I'm extremely hesitant to apply spoilers on landing. Every piece of me screams that you do not ever want to decrease the lift from your wings during landing. Luckily my radio has a knob that will let me apply either flaps or spoilers depending on which way I turn it. I'll experiment with both ways this morning and see how she handles at slow speed and high altitude.
My understanding with the full size airframes is that you apply spoilers after touchdown so that more weight is transfered from the wings to the wheels to make braking easier and is totally undesirable on an approach because it reduces lift without affecting drag.
Too bad she doesn't come equipped with decelerons or some other airbrake. Maybe I need to rig a little parachute like the space shuttle.
G