it's worth the $$$ buy from YadkinGuide on here. He has the best price.
I use one and you can do so many things with it it's crazy. You can add a table between the 2 seats or even make a rod holder to hold your rods when moving from spot A to spot B.
You can also just use a single seat in the middle or just one arm in case you are fishing next to a young child or something you can be closer in case they get out of their seat.
I recently made an umbrella holder using one of the arms. Here's some pics of mine.