what you want in a shoe is a stiff sole for power transfer, a grippy bottom( no matter the style) for climbing on a hike a bike, avoid , if possible shoe strings, unless they have a "lace keeper" like my 661 Nuevos to hide the extra string in because they will inevitably get hung in your chain, gears, something. a snug fit is also a big plus but not tight to the point of pressuring the top of the foot.many now have 2 vecro straps and a ratchet buckle at the top for a truly custom fit
661 shoes run 1/2 size smaller than other shoes.Ex: you wear a 10.5 Shimano shoe, youd go with an 11
661 are available at JesonUSA but Ive never seen any locally here
I have a pair of Shimao M180s that fit really well, are super stiff and ratchet at the top. the toe spikes should NEVER be removed though, no trction at all without them
I also have a pair of 661 Nuevos that are super stiff on the bottom yet all day comfortable on the upper. they have laces so custom fit is out. they also have a skate style outer sole for supreme traction with no spikes
another factor is ventilation. yes for warm weather, no for cold weather,unless you use booties, toe covers or such