I can't comment on those systems but I've been through a variety of iterations of righting systems and have come to the conclusion that a righting bag is the best solution for me.
I have a giant righting bag:
http://www.murrays.com/mm5/merchant.mvc?Screen=PROD&Store_Code=MS&Product_Code=01-3280&Category_Code=In addition, I have a separate righting line that is attached to the dolphin striker. I have loops in the line from the dolphin striker and then I can connect my trap harness to one of those loops and stay suspended just above the water line. Then I have both hands free to deal with the righting bag.