I was in fact wondering why it couldn't exist in both but didn't dare to ask. But of course, that would be great!I plan to offer "Seamless Wave Looping" also on the Preview Tab. That way you can control the playback completely by keyboard.
While I'm at it, I'll be brave and ask...any chance of getting back the progress bar in status bar instead of the green 'Looping', along with the mouse-down controls of FF & Rewind? But that's just an icing on the cake, far from essential if the Preview tab will offer all the controls. It's just looks cool & can be handy sometimes
As for the question...not sure, it's hard to say now. I think one can form a better opinion once you start using it more so for now I'll go along with whatever you favor