I know this post isn't very original - I've missed a great deal on a new 105 FD-5500, right clamp (28.6) 9 speed double. So now I'm looking at the Sora FD-3400 seems pretty darn similar, I'm not concerned about weight or bling, just good function.

I'm doing an 8sp cassette, 9sp chain, friction shifting on a compact sram crank for a bike build. I've seen great deals on 105 10sp FDs, but I don't think I want to deal with endless chain rub, so I'm pretty committed to 9sp.

Anyone have experience with the sora fd specifically?
Old 105 FD tech vs newer Sora FD tech?
Am I over playing the chain rub issue?

Thanks