Guess I'm the odd ball in the bunch but I've never needed more power outlets than what they have on the ship. I don't take a laptop, as I don't need nor want to be " connected " 24/7-- I take a cell phone--no charger, as when I get to the ship, I call my son, let him know we made it ok, the phone goes into the safe and doesn't come out til the cruise is over.
I take a digital camera battery charger and use it some but that's it. I don't use an electric razor but if I did, there's an outlet in the bathroom for such a device.
There's a hairdryer in the cabin should we want or need to use it-- we go on a cruise to be on vacation--vacation means to vacate--get away --be out of touch from the mundane, everyday rut lifestyle-- not to be loaded down with the same daily workloads and worries you have at home-- if you don't cut loose from it, why spend money and still take all the worries with you? If you can't get loose from work, worry, problems, then don't go until you can.
Cruise--relax-- get disconnected and you might be surprised that things go on just the same without you and that you may be a little more refreshed from your vacation if you truly " vacate " instead of taking everything with you.
Just my humble opinion that means nothing to anyone but me. ;-) ;-)