Can't say I've ever tried the windows version, but the Linux version worked pretty well for me. Compared to Palm Desktop? Can't say... Palm Desktop is pretty hefty... I don't believe the aim of Osmo is to replace it (and there is no Palm Desktop for Linux that I'm aware of).
For what it does, and what alternatives are available natively on Linux, Osmo does a pretty good job. The UI issues you're having are probably due to the Windows port... I don't recall seeing any of the strangeness you're seeing.
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