I have the Downtube mini, it's a good bike.
I would have gone with the Greenzone if I had known about it. $140 less than the mini when you add the shipping.
Also it looks like the Greenzone has a better handlebar stem that includes the quick release for the handlebar.
For folding, the position of the brake levers can be a pain. This handlebar stem takes care of that.
If front fender is important the Greenzone has one.