Speaking from sorrowful experience, it's hard to let go of a broken in, expensive pair of leather shoes just because the tread is done. Now you don't have to. This system is available with the Action SRS MTB shoe and Avalanche downhill boot. Sidi's stalwart brand is the Dominator, but they offer several models for different price ranges - all quality shoes. Sidi's Dual System allows adjustment of your shoe rigidity in the Energy SDS Road Shoe.
Many brands offer mesh or all-leather options.
Consider the weather you ride in most often. Carbon-soled shoes are the stiffest, and therefore the most expensive. But other less-expensive plastic soles don't drop much in performance, and actually work better for walking into the bakery at a ride break. Northwave, AXO and Shimano are other reliable brands to consider. Don't stop at the shoes if you're looking for total foot comfort.