As for fast, my versions only use a 120W 1400kV motor and are faster than my FT Spitfire. Extremely aerobatic and the most insane maneuver is to power on dive vertically from 300+ Feet to just above the ground, The added speed allows the thing to do loops around 4ft in Diameter.
The stall characteristics are rather benign. If the CG is correct it just seems to sink with full up elevator with a nose heavy attitude it nods the nose up and down as it stalls and recovers all by itself. With a tial heavy setup the plane will loose directional stability and wander from side to side before it suddenly drops a wing rather savagely, (The more rearwards from the required CG your plane balances the worse the stall behavior becomes.
Only real issue is ground effect if the plane is too low as it will balloon close to the ground. If you land hard whilst feeding in up elevator it can do an insane loop after bouncing off of the ground and then land upside down. Ideally we release all elevator at the moment the plane touches down or is about to.
The fins are for directional stability and so far I have not seen much difference between fixed inboard fins and winglets except for how the plane handles in a very strong crosswind landing. with winglets the plane tends to wag its tail a little and with the more central fins it seems ot roll a little more.
Have fun!
