I was initially working with struts1 and found it very limited with ajax. I migrated to strust2 and what can I tell you...I love ajax. Struts2 has a lot of methodologies to integrate ajax and as a result the user-experience is much better (application is user friendly) and the application is faster.
sorry for my delay (bizz trip). By "application is faster" I refer to the user-experience, or in other words the application is more user friendly.
In my strust1 applications, when the user clicked a button there was some process in the background and the info was posted back to the user (an entire new page) this took fairly a lot of time.
The combination with struts2 and ajax is great from 2 aspects: 1. learning curve is fast (you'll get the idea quickly how to use ajax tags) 2. (with reg to the prev paragraph) when the user clicks a button the info is returned to an ID on the webapge (without the need to refresh the page) so this is what i meant by fast (i guess this is the idea of ajax:-) )