Although heavy, the 680FP has great power and should be a good short field performer.
Jim Metzger taught me how to do short field takeoffs in the 520, and it was a real eye opener what can be done with Commanders if you need to. 2/3 flaps, yoke in your stomach and the 520 started climbing out at around 45kts. It was insane. A 680FP probably a bit higher, but once you get comfortable with it, you should try and see what numbers you might get. Think you will be surprised. BTW, none of this was published stuff from the POH, it was just Jim's experience.
Remember, the stall speed power on is significantly different from the stall speed power off. On the 520 the power on stall speed was an insane 35kts. Can't remember the stall speed dirty, but it was quite a bit higher, probably around 49kts. So if yours has a stall speed of, let's say, 60kts dirty, I bet it's around 50kts power on, which is what you'd use for a short field takeoff.