I believe that IBM 1.3 jdk is faster than Sun 1.3 JDK, according to many benchmark available.
However, for 1.4 version of JDK, I can't find any benchmark, anyone try to compare Sun 1.4 JDK with IBM 1.3 JDK with JBoss?
Even if it might be slightly faster (I don't know), I don,t think you should use IBM's JDK, no matter which version, and the reason is simple : it's _not_ standard. Every IBM JDK release is a hodge-podge of different versions, some parts of ulterior versions and some parts of older ones... It works ok with VAJava and WebSphere, but with JBoss?! You should be careful.