I have been printing tens of thousands of labels with my 330 Turbo - still it is *impossible* to switch over to the OSX version; I have to do all my printing in Classic (which doesn't work half the time either; sometimes even a complete reboot is necessary - I assume it's a driver thing). I filed several bug reports and inquiries, Dymo was very responsive at first, but absolutely unwilling to solve issues or even confirm them, they call it a "feature" (I think I heard that somewhere else, too).
Just one simple example: create a barcode as broad as possible in Classic, then load the very same label into the OSX version - whoops.
Another issue is the completely different rendering engine (looks like they started over from the scratch for the OSX version, which is a good thng per se), fonts and therefor your label layout is a whole mess when importing your Classic labels into the OSX version. Well, 0 (zero) stars for this one - mainly due to the complete ignorance.