Now onto my next upgrade... a new rear hub. Nearly decided upon a 120mm Profile Track Fixed/Free Hub with an upgraded 14mm chromoly axle (so I can use rear pegs) and an Elite 16T Freewheel screwed on. Also considering a Resist ICON with a WI ENO 16T.
My current BT OWL rear hub, although virtually bombproof and considered by many one of the strongest fixie rear hubs ever created, sadly only offers 30mm BMX M30 type threading. This severely limits me on what kind of freewheel I can screw on... not ISO M35 (1.375" x 24tpi) threading so I am unable to use an ENO, ELITE, MONTY TRIALS, ECHO, nor even a Jitsie freewheel.
I'd go with the profile, I really like my elite freewheel. Noticeable drag while it broke in but now it's great. I went from the white industries and it definitely feels like an upgrade!