Yeah, a few of the Ocean folks have actually made the jump to Mysto due to some frustrations with the Ocean software. Helio has kind of dropped the ball on some nagging Ocean features (MP3 playlists and album art are still not fixed, PC Link has not been rolled out for the Ocean and data/contact management is totally reliant on third-party stuff), because the word is that SK Telecom and Pantech are working on a new and improved, Windows Mobile-enabled model. And thus, why bother working on stuff for their current model running on an outdated OS (oh, I dunno, because it's the only reason you have any subscribers!).
The Mysto has very few bugs and PC Link Pro out of the gate (the ability to sync calendar and contact information), and runs smoother than the Ocean. Plus, its MicroSD slot supports up to 4GB and the Ocean supports just 2GB.