Darreld-

Coil spring. Lockup is not real tight but not excessive. So far timing has been perfect. Probably have about 200 rounds through it with zero problems. Finish is not great but does the job for the price and seems durable. Accuracy is very good. Single action and double action trigger pulls are very good. I have not weighed them. Hammer is long - may or may not snag depending on how you carry it. They do make, as you noted, a DAO version - no hammer spur. Comes with two grips - the classic wood and larger rubber type. The wood grips are "cute" but once you try the rubber you won't put the wood back on IMHO. Armscor seems to consistently get very good reviews on all their products.
I can't afford a good fart right now so even in the $250.00 range I purchased mine on layaway. Bottom line - I highly recommend these - based on the experience I've had with mine.