2 things on the homepage that might turn away web-developers before even trying to download MODx:
makes child’s play of building content managed sites with validating, accessible CSS layouts – hence Ajax CMS.
CSS hence Ajax ??!
quite inaccurate, it really reads just as buzzword stuffing!
It empowers its users to build engaging "Web 2.0" sites today, with its pre-integrated Scriptaculous and Prototype libraries
Why making it seem like you have to code in scriptaculous, when infact it is equally easy to use any other javascript framework a developer might had invested time in!?
SEO-wise the following might work better:
(...) makes child’s play of building content managed sites with validating, accessible CSS layouts.
It empowers its users to build engaging "Web 2.0" sites today, by integrating Ajax functionalities from Scriptacolous, jQuery, YUI, Mootools, Dojo or any other advanced javascript library.