I have all of the listed bipods and a couple of additional models. The rock creek barrels SOPMOD bipod is very good for the money. They had a group buy on the hide for $125 which was an excellent bargain. The Atlas bipod is also very nice for precision rifles.
http://www.rockcreekbarrels.com/new_page_2.htm
http://www.accu-shot.com/atlas_bipod.html
I have to say the BoBro is my favorite overall, its very smooth to operate and stable. They are so damn hard to get though, thats the downside. I had mine on back order for nearly 6 months direct from Bobro.