Still have to test it, but I do not expect to find any difference in the ability to charge the FP.
I own the Power 10 as well as the Power+ and I absolutely love them.
The Power 10 really is a heavy-weight but feels very good and sturdy.
In my opinion the Power 10 and Power+ are really hard to compare, as they aim at different fields of usage.
The Power+ is lightweight, has an integrated solar-panel, a footstand to position it facing the sun and a torch. The torch can be used with the footstand as well to work as a light for reading etc.
Therefore it is handy and fits into even small lugage for a daytrip charging the phone on the go, sitting in your briefcase.
The Power 10 on the other hand is a kind of sturdy “brick” and definitely not for the briefcase. For solar charging it takes a separate, large, foldable panel. That’s an equipment for home use or for the camping trip. At least you will want to carry it in a suitcase when travelling. Two torchs come as separate parts, one of wich only working when connecte to the Power 10, as it lacks a battery.
But if you will use the power-bank often and maybe for different devices, the Power+ might not be powerful enough to suit your needs.
When it comes to the looks, I love that yellow colour.
If you don’t, the Power+ at least on amazon is available in black as well as in white besides yellow. The black and white versions are no longer available on the waka waka homepage; a while ago at least black was still available in their online shop.