Took my new SP5K to the range for the first time today, I have to say I am SOLD on the roller-lock design, this thing is awesome! I don't know how to describe it accurately, but it's obvious that it is a full-auto design adapted to a semi-auto, it's just so quick. I was running drills to prepare for an upcoming USPSA match next weekend with my VP9 competition gun and also ran them with the SP5K. The SP5K is faster (granted, I didn't need to reload) and the splits were 0.16-0.19 vs. .19-.21 with the VP9. I was just using iron sights, but considering putting a red dot on it. BIG QUESTION: Can I shoot this in USPSA without a stock on it? It appears to not qualify for PCC since it doesn't have a stock, and not qualify for any other class since it's not in a holster.