I use them almost every time I am on the boat...I wouldn't use ANYTHING but my OFFSHORE Side Planers.
They are easy and fast to release, so you can get those big fish into the boat, and they hold on pretty well, even in big water. The trick is how you wrap the line around the quick relaes button...no putzing!
I certainly would NOT buy those "universal" planers...there should always be one for the right and one for the left...unless you're running TWO on each side, like I often do.
WELL WORTH THE CASH!