Mine's a Santee. And like you mentioned the same frame as the Hardcore II.
I paid about 600 bucks for it and didn't really expect the world for that price but I'm really pleased with it. The welds look like porn, the motor and transmission mounting surfaces were true, the backbone is double tubed (a tube within a tube,) and it has a nice thick gusset supporting the neck. The tubing is 1 3/8 and overall it's a beefy looking frame.
It's the first single down tube frame I've owned and some warned me about that, but I can't tell any difference. Hands off the bars it tracks straight and slight turns are easily accomplished by weight shifting. I've had it through all the speed ranges on lots of different surfaces and so far no wobbles or anything out of the ordinary. Also pretty much everything "Softail" fits this frame parts-wise like brakes and whatnot.
I just looked and there's about a half dozen of these frames on E-bay right now. The price has gone up a bit, but overall I would've paid a grand for this frame and been happy. I'm not sure Santee is still making these frames and the ones for sale now might be leftovers from when the kit bike market crashed. At the height of that craziness those Hardcore kits (with a Revtec drive line) were going for close to 20 grand!
BTW, According to the MSO and shipping info I received with the frame it was indeed built and shipped from Visalia, California.