So far my Intertap (from China) has been holding up well. Maybe I am lucky but with it working I like it much better than the 630PC's and 525SS's I have and was about to buy another one. You guys have me holding off that now.
Seeing that Williams Brewing is going to carry them again, and yes the US patents listed did recently appear and appear to be "Ventmatics" patents, maybe the solution would be for someone to contact William's Brewing and strongly advise having spare washers and O-rings available, even if that source is from McMaster Carr initially?
I don't mind really having to occasionally replace O-rings. I certainly have done it more than once on the Perlicks. And yes, I've had leaks on both of their styles too. The weakness of forward seal is the bonnet/handle leak. Still for our uses that is a good tradeoff. But I understand that is why the rear seal was developed in the first place.
The other option would be to get a group buy of some sort going for the metric washers and O-rings to do the conversion listed here. It seems to me (but I'm an electrical/software engineer, so what do I know?) to be a little overkill but it certainly is probably a permanent fix.
I wouldn't write these off yet by any means. I think KegKing will likely need to get their Chinese manufacturer to improve the machining a bit, get the seal issues resolved and probably price it for a few dollars less in the US, anyway, than the Perlick for it to be really a hit here.. but the potential is still there. I like the way the one I have pours and I really like the stout spout.