Foundation paper piecing was never my favorite. I think it's because I used it for pictorial subjects, where all the little patches were very random shapes, and it's sometimes more difficult to figure out what size piece of fabric to cut that will cover the area but not waste fabric, when working upside down and backward. I always felt there was a lot of waste.
But using it for geometric blocks is a whole 'nuther story! You can measure each segment, cut patches that are the right shape and a bit larger with minimal waste, and know that when you flip the patch over after stitching there won't be the "DOH!" moment where it's just a little too small. (I know you know what I'm talking about.)
And the points and corners and lines are so crisp and straight, no matter how small the patches. Removing the paper is still a pill, but the results might be worth it, if you're working small.