I've been experimenting with single speed, because, why not: But I really miss fixed - so it's flipped back to fixed, and the flats replaced with SPD pedals.
I'll try again when I have the time for long distance: I expect I'll enjoy single speed on some long rides.
Every time I lift the mono, it feels light as a feather: My geared bikes are 2 and 3 kg's heavier.