Working with the new Eclipse Ganymede for a while now, and on my Mac it is worthwhile: faster and more stable. Except for Mylyn/Mantis. Mylyn is a resource hog, and the mantis connector doesn't want to store my updates to tasks in our mantis installation. I synchronize my ass off, but no f-ing way that the carefully crafted status in my workspace is sync'd with our tracker.
Gawd... I hate these halfbaked solutions.