More wieght, electronics, hydraulics and a good amount of money for something you are going to get rid of later this year? Plus extra holes in the transom. Doesn't seem like it's worth it to me, I'd rather it be brand new when rigged on a new/newer boat.
I've fished off a few boats rigged with double PP's. The only difference I noticed is your boat won't swing around to adjust for wind and flow. A lot of guides use doubles because it lets them position the bow right where they want for the clients, on your personal boat you could just walk to the back deck, or cast off the side just as easily. Unless you are doing fly fishing, I could see wanting the bow pointed for that, but still not really needed. Many tournament guys run duels too, but it's because they are sponsored, not because the use or need them. Kind of like the sponsored boats you see with mixed brand motors on them.
So in short, IMO, yes it is overkill, no it is not worth it, and most likely won't help you catch any more fish.
