Kiko- are the martins cages 1/2 inch spacing correct? They seem pretty nice. Any negatives you've noticed? Id imagine cleaning isnt that easy, at least it doesnt look like it would be. Ive never heard of the fiesty ferret either, who makes that Lauren?
I am not sure of the maker of the Feisty Ferret, maybe Prevue?
http://www.ferret.com/item/feisty-ferret-home/600999/The only downside is that only one door opens per level and that the top floor is wire which has to be covered. I believe for the bottom you can put it together without using the grate and so you just have the pan. Some people cover their levels with tile, linoleum, etc.
http://www.goosemoose.com/component/option,com_smf/Itemid,118/forum,rat/topic,4029430.0^ This thread shows some pics of it in use and decorated and also has a good pic (on pg. 2) of one next to an FN for size comparison.