Well, I'm in sidemount heaven!
I picked up my pair of Mk19/D420's at the LDS today! Hats off to Jon Edens at Marin Diving Center, San Rafael, CA!
So here are the test results. My serial numbers are one digit apart, so there's a 50/50 chance it was the same technician who built them.
Set #1:
2700 psi (sorry, shop tanks not quite full)
IP 141 psi. Crisp lockup, no creep.
D420 cracking effort: 1.4" WC
300 psi tank
IP 147 psi. Crisp lockup, no creep.
D420 cracking effort: 1.3" WC
Set #2:
2700 psi input
IP 138.5 psi. Crisp lockup, no creep.
D420 cracking effort:
0.7" WC
300 psi input
IP 143 psi. Crisp lockup, no creep.
D420 cracking effort:
Slight Freeflow!!
When I took the purge off, I expected to find the valve lever tight up against the diaphragm.
But in fact, they'd done that part right. There was a little tiny bit of taptap between the diaphragm disk and the lever under pressure. So I'm assuming it was just a knucklehead failure to put enough spring pressure on. I'll pry the disc off later and fix it. No big deal.
Conclusions:
1. Mk19 IP spread is 4.5-6.0 psi, full tank to empty. Not bad!
2. Scubapro techs still haven't quite gotten their act together in tuning the D420.
Can't wait to dive the Mk19's. They look to be the perfect thing for an easily environmentally sealed turret reg, since I refuse to dive a Mk25. The IP spread is perfectly acceptable.
As for the D420, If you work on your own gear, we have a great reg here. If you expect it'll be good to go right out of the box, well, I think we're still seeing growing pains.