I have a SBT welded crank I picked up for the 97' GTX project last year. Yes, they do weld the pins, something to do with that when you reman and reassemble, you could get crank twist. I'm sure a new crank it's fine, crank twist shouldn't happen, so this is why they weld the pins. They still take back their own welded cranks later, I did ask that question when they called to review the core return policy.
I have no issue thus far with it, prompt shipping, easy to rebox my core and drop it off at the nearest FEDEX. One shipping charge that covers the return. I hear they use cheap bearings, but only time will tell on that one. Right now, a 787 carb crankshaft just went to $295 plus shipping, with a good core return. I'm about to place an order next week for another one to finish the 96' GSX resto project I'm working on. The crank I have isn't too bad, just one of the inner bearings is a little noisy.