I also didn't experience any malfunctions as misfires. Every round chambered fired with a single strike. Ejection was positive and, thanks to the sharp recoil of the .45ACP cartridge, the brass was cleared fast and well. I found some ejected brass as far as twenty feet away. Reloads were quick and easy as the magazines fell free of the mag-well with a good push on either side of the ambi-mag release.
I wasn't shooting to test fine accuracy, but throughout my afternoon of shooting, I had no issues keeping all rounds inside the 8-ring (rapid fire) and the 9-ring (slow fire) on a standard B27 target. On a TQ-15 target I was able to easily keep everything inside the smaller of the two boxes. Recoil was more than manageable and was even referred to as "comfortable" by a female student shooter on the range that afternoon.
As a long-standing fan of both Glocks and the .45ACP round, I've found myself thinking longer and harder about the G21SF. Again, while the Picatinny rail on the dust cover doesn't matter to me, I appreciate the versatility of the ambidextrous magazine release and the increased shooting comfort had from the slimmer grip profile. If you haven't had opportunity to handle one of these weapons, seek the experience out. Take my advice though: don't shoot one unless you have the money to spend adding it to your collection.