Just released Eclipse4Web version 1.0.2 has a support for MyFaces 1.0.8.
Sun Studio Creator and Eclipse4Web belong to different categories of software.
Sun Studio Creator is a visual tool. It provides the visual paradigm how to develop the web application. Actually, the major idea was creating the analog Microsoft Visual Basic, but for Java. It is very easy to use if you create small applications. It does not required too much knowledge about JSF to start working with it. Creator creates two-tiers applications. JSF itself holds the MVC (three tiers) paradigm.
Eclipse4Web is not a visual tools (At least, right now). You have to know JSF technology in order to work with it.
P.S. About "buggy": Almost all the reported bugs was about the recognizing the custom (
struts) tags declared directly with tld file. in the JSF, the taglib is declared with URI="http://". So, it is aside problem for JSF.