compact or long LP10

[Tycho]

That statement is too absolute. There are posts on TT from very, very good shooters who prefer short APs to long APs - look up the threads about the short Morini 162. Sight radius does not really matter in AP, the 10 ring is large enough. There are national team shooters using short APs instead of long ones. If your hold is good, your subconscious may be able to shoot better with a short AP, as it oscillates less and stabilizes more quickly due to less inertia. On the other hand, for the same reason, the short pistol reacts more agressively e.g. to trigger mistakes, as there is no mass out there in front that dampens the movement. On the LP10, you can move the rear sight backwards, giving you pretty much the same sightline as a full size Morini, and the current world record holder uses a standard length Morini, so that's clearly not a big issue. Balance and inertia is, though.