We are running our applications on .NET 3.5 and are planning on either updating to .NET 4.0 or switching entirely to the Java platform, J2EE v6, as we've heard from some clients that "it's better." Can anyone either explain some of the large differences between the two platforms and maybe what kind of costs would be associated with switching to Java rather than just updating, or point me to some articles or papers that make such comparisons? Thanks!