st3v13,

I say go Steamroller. Everything about the Steamroller is solid - everything. Plus, as my pictures and others have shown in the Steamroller porn thread you can work on them and make them as Plain Jane (mine) or as gorgeous (pretty much everyone else's) as you want. Steel is good for fixed gear frames for a number of reasons but a few of the more practical ones are:

1. They provide a solid measure of compliancy. You see, on a fixed your butt is firmly weighted in the saddle. It's surprising how most people - even long term cyclists - gently unweight themselves in the saddle. This really can't be done on a fixed gear. Your body weight is on the saddle and there it will stay. A frame with a smidge of comfort is much preferred unless you only plan to ride the bike for 30 minutes or less at a shot.

2. If you treat a steel frame with that canned grease stuff (go to LBS if you don't know what I'm talking about and have them do it) the frame will last forever. 15 year old steel frames are in their prime.

Cannondale lost it's shine for me when they moved their welding overseas. I happily paid extra in the past for Cannondale for that little sticker that said "Handmade in the USA". No more sticker so no more sparkle for oldfixguy. All the others you mentioned are pretty much on the same level playing field. Purchase by stock components and aesthetics.