I assume you will be racing mostly in MABRA (mid-atlantic) events. The mud we get here on the East Coast, in general, is not quite what you see in the Northwest (check out pics of nationals in OR...) or the big cyclocross countries of Europe. You still see plenty of mud, just not swimmin in it- in fact the early season is generally fairly dry here. The point being that the main advantage of a top-pull front derailleur is to keep the cable high away from the bottom bracket in soupy mud. Top- pull front derailleurs designed for double cranks with larger rings are rare (I'm not sure if they exist at all, I've never seen one). Top pull derailleurs were designed for MTB cranks, not cyclocross bikes. They have some advantage in nasty mud or freezing slush, but in moderate or dry conditions they just don't shift as nicely as a nice familiar bottom pull road derailleur that was designed for ring sizes like 38-48t. I have 2 bikes, one with each kind. 90% of the time, I'd rather have a regular bottom pull derailleur for a double ring cross setup. And that other 10%, well, ain't nothing working then. Your problem is always at the back end with the cassette and at the brakes in that kind of mess. Which is why its nice to have the luxury of 2 bikes to switch out. Anyway, for East Coast racing, I'd go for a bottom pull derailleur setup, or even better, to cover all your bases forget it and just use a single ring (like a 42-44). I see lots of dropped chains in the C races from people bouncing their bikes on the remount. A single ring will keep the chain in place and you only give up 1 top end and 1 low end gear. Keep it simple-