The valves use different on/off valve pin lengths. Can't recall the exact dimensions but I don't think an Emag pin will work in a regular automag. Other than that pretty much all of the later valves (RT, RT Pro, Xvalve) will drop into a classic. Just avoid the classic RT because they take air feed in from bottom through the frame rail. ROF is down to input air pressure and trigger frame set up. A correctly shimmed ULT trigger and 1000-1200 psi feed to valve should get it hitting 20+ bps
The one in this video is owned by Justin - a friend I've played UWL with
It shoots through a 140 ball reload in about 7 seconds, which works out at about 20bps