When I received my 630's, I took both of them apart just to double check everything was good, including the forward seal, and then reassembled and installed. When I took them apart, I noticed that on one, the upper "ball" on the lever didn't enter the spout housing as deep as the other one. I removed it and re-installed and it got it to sit deeper. that allowed me to get the bearing cap to seat correctly.
These are not very complicated items, so I would bet that the issue can be limited to (1) the lever not being installed int he correct position (too shallow), (2) the bearing cap not tightened to flush, and/or (3) the forward sealing o-ring being defective. I would ask perlick to send me a new set of o-rings, take them apart, and reassemble with the new o-ring.
If there is a light at the end of the tunnel, I love my 630s. They are great, the pour is significantly better, and they seem to be more sanitary. I usually only pull one beer a day, if that, so during the week they sit unused for several days. I have had no sticking issues as I did with the standard issue faucets.