I've used both BD's and Smiley's. I've found that the Smiley's are not as hard as the BD's. The threads, over time, get dinged up. So, even though I kept them sharp, after a while they tended to screw in harder than the BD's after the same amount of (or even more) use. Hanging from one tired arm, a little hard to turn is a big deal. Especially when you really really want to get that rope clipped.
Generally, you get what you pay for. There's a reason BD's cost more.
My two cents,