Today I went back with the cut-down 10lb Wolff spring and it's shooting like a dream. It's just as reliable and feels so much like my Witness pistols. I did have three of those Perfecta rounds that made the weird poof, but kept chugging through 100 rounds. Looking forward to getting the 10mm version now.
I went back today and ran another 100 without any cleaning from the last visit. It just runs now!