• working with JSF components in general and ADF Faces (11g Rich) in specific is very productive
• however, with the productivity, you sacrifice some of the control over the look & feel (that is: almost anything you want to do can be done, but some things take considerably longer than would be the case when having full control over the rendered HTML)
• the shipped skins in ADF 11g RichFaces produce a look and feel that is more than adequate for most applications (that you develop without having to resort to Flash/Flex in the first place); within the skinning framework you can achieve quite a lot of customization to the look & feel in an organized and fairly productive way. For some wilder things, you have to jump through some hoops
• Mr. Skinny’s suggestion about combining Skins at the component level and CSS at the page (container) level could work to some extent. Of course skins apply to the containers within the page as well, so you may not need the external CSS files at all
• Jan is overstating the situation in a fairly dramatic way: the productivity gives you more like 90% of the application; if it does not, you may have to consider a different development technology stack. However, most applications that are not primarily marketing vehicles or mass-consumer websites will fall within the category of applications that benefit from the productivity gains a component based development approach can give you. Not just in development, but also during maintenance when the application is adapted to satisfy those ever changing customer requirements.

In conclusion: many applications – for backoffice, intranet and internet environments – that support task or data oriented processflows and where graphic visualization and interaction – drag and drop, animations, rich media – are not of primary concern will benefit from a component based approach in terms productivity and complexity control. Through the skinning mechanism they also allow a fair amount of engrained Look and Feel customization. Additionally, you can use external stylesheets for the final tweaking. However, for applications where a custom(izable) user interface is the primary concern, a component based approach may not be suitable.

Since JSF is ‘sooo flexible’ and allows for ‘Pluggable Rendering’ as is described also in http://www.oracle.com/technology/tech/java/newsletter/articles/introjsf/index.html, this shouldn’t be that hard right? I see a lot of statements like ‘Components provide productivity…’, but I’m asking myself what is the value of this productivity in the first 20% of the project, when you have to work the other 80% of the project, trying to alter and/or enhance the UI based on the (ever changing) customer’s requirements or new insights.

Using components should not make this approach more difficult. By decoupling the logic and generated output of a component the rendered HTML could be formatted according the rules of the designer. One way of making this possible is to give users of a component the ability to supply a template it must use to generate its output.