I just think that having no obvious limitations invites to work on a song directly.
I'm all for being able to work on songs and to listen to the way Z2 lines up with other gear and to check if it fits the way one works.
Another problem would be... you will certainly want to check out the presets. Thus some sort of loading must be possible. I think it would be a stunt to put something into the presets that distinguishes between the ones that come with Z2 and the ones made by the user. If I only restrict that to presets that are saved with song, people will just save the presets manually and load them up when they continue on the songs.
Several people told me that they simply work with Z1 until it plays wrong notes, load the song again and freeze the Z1 tracks. Fortunately, they get so fed up with this style of working that they surrender and buy it
Nevermind, demo restrictions is a science on its own behalf. Everything has got pros and cons and I'd really wish we'd live in a world that worked without them.
Cheers,

