Great choice, I've used these for the last couple of years and wouldn't want to change back. The paper does work very well with fountain pens but can take a while to dry so I've got a couple of pages of blotting paper in mine to speed things up.
Oh lord.
I'm already planning on getting a Hobonichi planner as there is one that starts from April, 2016 and it's apparently THE planner for fountain pen users... Sigh... Hello wabbit hole!