I don't agree with keeping rats in tanks (Rats are not equal to hamsters or mice for that matter, their care are completely different, be it dietary and cage wise and to compare them really isn't right. Just because they are "rodents" dose not make them the same-neither is comparing hamsters to mice or let's say gerbils), but I (as an experienced owner) have kept hamsters in tanks with ventilated tops.
I also use bin cages with ventilated sides and tops for years with no problems.
Unfortuantly, a hamster (esp a dwarf) cannot go into a FN or CN, nor are ANY of the pet store options adequate, even with extensions. They are never large enough, clean enough, and more over, I am not paying $40 for a cage when I need to buy 10 of them to get the same space. If someone gave me viable solution, I would take it. There are precautions to take in bin/tank cages..such as where the tank is kept, what kind of bedding is used, ect.
And as cat owners, I would be wary of buying pet store cages with cats as they are way easier to break into or paw in.
And Minka, how is a bin cage any less ventilated then the crappy critter trails or other *ahem* PLASTIC cages? That is what I really don't get...most CT and others have plastic tubes, sides, and about 1/2 inch if not more of solid plastic on top and bottom and a solid roof. So you get bar siding. How is that any different than bin cage?
Again, I hear the argument against bin/tank cages with no viable options otherwise.

Elli, I have posted on HH but your cages look good

I love Kodi.