Hi,
i had the same problem. In the end i chose Cambridge because
1. it was easier to get it in Central Europe
2. it has bars and my hamster does not chew them so thats ok
3. no tubes in Cambridge. I dont think i like them and my dwarf hamster could have problems climbing up them, so i decided i like ladders more
ps: you can read that its hard to get the shelves in the cambridge to their place, but its easier once you put it together for the first time