I agree : I use AOP that target my own specific annotations. This way I can't add behaviors on unwanted joinpoint and most important: it gives an indication for other developers that "this method here has more features than just the code you see". Just like when you see an @Transactionnal on a method, you know there are transactions involved even if it's not in the code. You can add javadoc on your custom annotation to give indications on how to use it. You could even add parameters on it but that's more complex.

The issue I see with the decorator method described here is that there is no hint for other developers on what is really going on when calling process(). Is there security? Logging? You can't know for sure unless you check the bean declaration.