I have both Sig and Zev barrels on my P320's and P365's. Honestly no difference between those two. From what I understand Sig manufacturers the 320/365 barrels for Zev. They shoot the same and no issues with accuracy or finish. The only reason I went with a Zev barrel on my X-Compact was because I didn't want the LCI witness notch at the top of barrel hood. Zev had one in stock, while Sig did not.