I'm beginning to think something like "Gel, a freeware Java and JSP IDE that runs natively on Windows" might be the way to go with Java IDEs. It's not like Eclipse is slow on Windows, but even there Eclipse is noticibly less responsive than native apps. Perhaps it's the size of the app -- all that Eclipse is trying to do -- but I suspect even with SWT you've got minor speed issues.

Curiously, .NET apps have a similar issue with slowdown. Perhaps it's b/c n essentially equals 1 for me right now and #develop is just poorly written, but so far the whole virtual machine route seems to include, almost by definition, a ton of overhead.