We have been using SP 2013 for its ease of use when it comes to developing workflows especially the copy & pasting thing in SPD. But our main production environment will be using SP 2010 for it's relatively faster when it comes to UI interaction based on our experience.
Now our problem would be, is it possible to save the list as template in SP 2013 and then uploading the template in SP2010 at least for the list... Never mind the list workflows... :)