With regards to my front brake, I've got a few different calipers to choose from. I've already installed a well-used Shimano 600 dual-pivot job, but it seems kinda clunky. I also have a brand new Promax dual-pivot caliper which seems pretty nice, and I've got an older Campagnolo Veloce single-pivot caliper I can throw on.

(My bike is an '86/'87 Bianchi Strada LX with Shimano 600 cranks and pedals, IRO hubs and Mavic MA3 rims, a Velo saddle and generic seat post, a Zoom stem and generic bars, and a Cane Creek "accessory" lever. The frame is blue, the wheels, cranks, and pedals are silver, and the bars, stem, seat, and seat post are black.)

Here are my concerns -- the Shimano 600 is one of my favorite brands/lines of bike parts, period. But it's old and some parts are rusty, and it doesn't "match" as well as the Promax. Speaking of, the Promax is brand spanking new and seems nice, but I don't know much about Promax as a brand (it seems to be a part of Leechi, which I have traditionally associated with cheap stuff.) On the other hand, Campy is a brand that can be trusted, but the older Veloce caliper I have is single-pivot and has no QR level.

Given that, if you were putting this bike together, which would you choose?