So why do I prefer Eclipse?
In the course of talking about it, I came up with my answer. Eclipse if built by top developers for themselves. VisualStudio is built by top developers for some other developers. Both IDEs were built by teams of some very smart developers, but Eclipse developers seem more focused on building a product that they themselves would want to use. Microsoft has a strong internal culture that says that their primary target developer isn't as good a developer as most Microsoft developers. Which do you think will result in a 'better' product?