Parametric Linear Bearing with Optional Split

I made this tonight since my X-Axis bearings were shot and carving a groove in my rods. My printer is working seemingly better than ever with these in place of the steel on steel bearings they replaced.

I printed these at half the "height" of the originals for now thinking this would decrease friction, but I might have that exactly wrong. Longer bearings may yield less friction since it distributes the load over a larger area. Try for yourself and please let me know what you think.