This was one of the bigger bento boxes I found on Amazon, and I'm glad I did. I could not imagine going smaller than 720 ml. I am a 20 year old girl, 130 pounds, so I don't eat a terrible lot of food. When I pack it completely full, like the bottom stuffed with rice and stir fry to the brim, and with the top stuffed with fruits, nuts and chocolates, I still throw an apple in the bag alongside the bento to make sure I've got enough. That being said, I am never hungry again until dinner time when I should be, and I am not too full either. So for me it's the exact right size, and I definitely see why bentos are good for portion control! If however you prefer an "American lunch" like a full sandwich, bag of chips, whole apple, etc.then I do not think this is the box for you!
The box and bag are just like the picture, very cute. I use the plastic dividers as plates and the chopsticks seem tiny at first but are just as easy to use as regular length ones.
The only reason I gave it 4 stars instead of 5 is because sometimes a thin layer of oil remains on the plastic after I've packed something cooked in oil (like stir fry) that requires more cleaning than just a quick rinse.
For the price I am very happy with my bento! Always wanted one and would recommend this to a beginner :)