I will say that I wear them hard. I mean, I live in NYC. I do a lot of walking. I don't wear sneakers ever so I am constantly rotating through dress shoes. I think I just need a combination for more shoes, and probably better fitting shoes that maybe won't get as stressed.
It's probably the sulphuric acid in the air and esp. in the rain water that is causing your shoes to crack prematurely. Large cities with lots of automobiles are notorious.
As for neatsfoot--it's great on saddles but not so much on saddleshoes. Too oily and too heavy. Lexol NF is supposedly a pure neatsfoot that has been homogenized but it will still stain light coloured leather.