In addition to having your knife performance tuned before it ships, you will received a coupon for complimentary re-sharpening of your knife (a $12-$50 value). That is the District Cutlery difference.
Masakage Zero knives are hand forged by Takeshi Saki with Aogami Super carbon steel clad with stainless steel. This is a great way to make a knife as you get all the performance of carbon steel (a very long lived edge, ease of sharpening and a silkiness when cutting) without most of the maintenance issues as cladding with stainless steel reduces the risk of rusting.
The Zero line from Masakage is an extremely limited edition.
Japanese chef knives are brittle and are designed for cutting soft tissue foods. High Carbon steel chef knives can rust if not kept dry.