I love my TwoZone - I usually store all my drinks in it along with anything small like cheese/dips etc. The Engel then stores the rest. Its awesome being able to open the fridge in sections, rather then rummage around to try to get to things.
I was VERY unimpressed by my TwoZone until I modified it.
While my Engel fridge would be almost freezing things, the drinks in the Two Zone would be moderately cold - as soon as you open it all the cold air falls downward out of the Two Zone and I imagine it takes some effort to cool it back down again. Found this on multiple trips and was cursing it.
What I did with mine is in one of the corners under the basket I mounted a 12v, 80mm computer fan blowing upward. Above it I made a duct that goes straight up almost to the lid and stops. What this does is allows cold air from the Engel to be fan circulated upward and over the contents in the Two Zone. Works like an absolute beauty now - everything starts awesomely cold and the fan draws a extremely low amount of power. You do lose a small amount of space but the gain in performance is more than worth it.
I'll get some pictures of the mods up soon.
Here is how it sits in my rear storage - the Fridge is a 25 year old Engel that I stripped back, sprayed white and replaced all the seals. As good as a new one!
A couple more (forgot to have the basket in this one - will get a shot of basket and fan asap!)