EA on Linux
With regard to your closing remarks, I use Enterprise Architect (from Sparx Systems) under openSUSE 10.3, by running it in Crossover Office. Specifically, EA comes in a version designed to run in Crossover Office. EA perhaps isn't quite as snappy running this way as in Windows directly, but it's still pretty close, and it usually isn't worth booting up Windows just to run it under Windows.
Cheers, Tony.