Hiya
the Gabber Rex is very difficult to get hold of, but it is a great cage!
There is a slightly smaller one which we also have - it is called a Gabber Lux and i think this is probably the one you had as it does have a rectangular shaped hole in the side for a type of water bottle which looks similar to a bird water bottle!! Yes, we have had problems with this gap too, but once we blocked it up it was fine
Old cd cases are great for this, lol!!
The Rex can have the same problems as it also has a hole for a water bottle which some hamsters will chew, but again this can be blocked up. Another chew point can be the holes on the sides where the clips fit into, but i havent had much problem with these, they usually get bord after a few tries
I have had determined hamsters chew out of gabbers but again, these can just be pacthed up - it is a great cage though
i love them!!
Tammy x