I've had both brands for a few years and once they're on the gun I really haven't noticed a difference in the quality of the two. They both have legs that lock into place using the same feature, they both seem rock solid, and both have a very similar swiveling mechanism. However, the two Shooters Ridge bipods that I've had are a pain (compared to the Harris) to put on your rifle.
I have no idea why it's harder because the design appears to be identical to the Harris but it always takes me at least 3 times as long (still under a minute) to get the dang thing installed but once it's installed it's golden. Since I usually just leave the bipods on my guns for a while the last two bipods I've bought have been from Shooters Ridge and it doesn't bother me that they're harder to get on and off since they just stay on the guns. I'm sure somebody will tell me it's user error that I have issues getting them on and off but my uncle, brother, and dad all have noticed the same thing. By no means is it hard to get the Shooters Ridge installed it's just a lot more difficult to put on than the Harris.
I don't have any experience with bipods from Caldwell but when I buy my next one it'll be a Caldwell just to try them out. Maybe somebody else could give some advice based on their experience with Caldwell's