Captca implementation in java

The three CAPTCHA libraries I've used for Java are:

1. JCaptcha - This is the most configurable of the three, and pretty well documented. But we can't seem to get this to look right, no matter what. It also does audio and other unconventional CAPTCHAs
   
   http://jcaptcha.sourceforge.net/
2. SimpleCaptcha - This is reasonably configurable, and pretty well documented. I like the way this looks, but some people have trouble reading it.
   
   http://simplecaptcha.sourceforge.net/
3. icaptcha - This is pretty poorly documented, but shouldn't be too hard to figure out from the examples. In our tests, we found this to be more readable than the other two (can be a good thing or a bad thing, depending on your target audience)
   
   http://code.google.com/p/icaptcha/

Our apps are Spring MVC based, and it was really easy to integrate these.
We just went with what looked best to us (icaptcha).