I love working with Jasson. On my original 5 mm, I had him copy with his rim cup measures from my Jettone Studio B (1970's vintage). He matched it to perfection (and I got it in gold as it feels so good on the lips). I use this one for lead playing. AND THE EXTRA BONUS is that I can add to the original front end, to a larger backbore attachment and that original resistance of the Jettone just melts away.
Then I had him duplicate my Kanstul G2 for small ensemble performance and again to perfection.
So last month, I got the bug to try the flattest rim he had, again, in gold. Then when I got it, it was almost unplayable when I substituted it on to the Kanstul G2. But I had some deeper rimmed options (that Jason includes with full kit orders which I had with my Jettone copy order), and took the deepest cup in the set and the larges backbore left in the set and WOW, I had an almost useless 5 mm rim, that NOW, with the cup and backbore turned the new combination into the darkest sounding and now most easily playable mouthpiece in my set. I am really loving this combination of 5 mm parts to when I play ballads. Just so soft, dark and sensual. Man does Harrelson 5 mms perform.
Totally worth the extra cost and with my last two combinations using prior kit parts, the rim only cost $100. So it was like getting an entirely new 5 mm for this price!
By the way, my original kit came with no charge through the deal I had for my trumpet purchase from him. The Kenstul G2 Kit did cost $450, but again, was it worth that to clean up the resistance of the original. ABSOLUTELY.