One thing that would be great to add to the overview (if you´ve still got the demo files) is how large the download is - it´s one of the things that spoke against Bryntum's solution (over 2 MB!).
Ext Gantt is actually only 287kb, and <100 gzipped. It does depend on Ext JS but only a few UI classes (TreePanel, Form, TextField etc), so using a custom built Ext JS should bring this down to a very reasonable size (nowhere near 2MB for sure). :)
GET ext-all.js
304 OK
cdn.sencha.io
442.4 KB
253ms
GET gnt-all-debug.js
304 Not Modified
bryntum.com
282.4 KB
251ms
With a clean Chrome, purged cache: I get "38 requests ❘ 829.55KB transferred ❘ 1.52s (onload: 1.07s, DOMContentLoaded: 1.07s)"
And this is still without making any effort to custom build Ext JS. We're using ext-all.js for simplicity, and to make use of Sencha's CDN which should speed up world wide access compared to us hosting a custom file.
/Mats (Bryntum founder)