First of all, hmr facilities either in AngularClass/angular-starter or in this repo are nor perfect at all.
They can't persist component state during switching procedure. Some values being persisted in the input is just some simple copy paste and remapping logic.
Both use the AngularClass/angular-hmr, which contains some helper functions for dom manipulations specially for angular. One difference is the hot update handle logic is copied into main.ts from AngularClass/angular-hmr-loader. Because it is unable to use angular-hmr-loader in angular-cli.
The other solutions on the web is even worse for now - 2017-5-25.