Chris Nokleberg's Fizzy Weblog
In addition to a cleaner API (for our purposes at least), ASM generates classes faster, and its small size means the total jar size is now 150K instead of 450K!
So, if your project can spare 150K, there really is no reason to still be using Dynamic Proxies. The Proxy class is a drop-in replacement which works under JDK 1.2 and can proxy any class. If you switch to the Enhancer class you also get a performance boost and more flexible interception possibilities.
p.s. If you're using Hibernate, you already have cglib.jar