Just riding around town is one thing, but for a serious experienced cyclist, fixed gear seems to accentuate ride quality. Without distractions such as shifting and thinking about shifting, senses get tuned to things like road feel, frame flex and responsiveness.
I've been riding fixed gear for a year and almost bought a high volume cheap bike at a closeout store. Instead I found a frame that instincts told me would be good for a fixed gear bike. So glad I built one instead of bought one.
I've been upgrading it since I built it to enhance the ride quality. The rims cost each what the frame cost.