The M9A4 is an amazing weapon, both in handling and design. It's heavy, sure, but that makes subsequent shots more accurate, less recoil. Different firing mechanisms though and to be fair I haven't shot the P320. But I love my M9.
I've only ever shot one on the range, but concur with the lack of recoil and easier follow-up shots. I can do hammers (controlled pairs) far easier than with a Glock 19.
