This is my Fixed wheel/winter bike commuter. 60’s Olmo road frame, parts bin stem, seatpost, crank. Mavic open pro ceramic front wheel, Cheap Omega rear wheel, Conti Gatorskin 28C tyres (big pot holes around here). Due to a change in my place of work and the need to negotiate a hill on a major road I have fitted a rear brake using clamps on the seat-stays to avoid the need of a huge 64mm drop caliper.
Lots of lights front and rear. Gearing is 44:16.
Used for my 30 mile round trip commute over rolling roads.
Riding Fixed over the winters has improved my leg strength, smoothed my peddling style and stopped me coasting on my road bike.
As for the biggest benefits, cheap, easy to clean and maintain and soooo quiet, just the hum of tyres on tarmac.