CritterTrail three or discovery delux?

I have a dwarf hamster and would like to add on to the cage she has.... I know as much room as I can give them is the best so I was looking at the crittertrail three but I'm likin the look of the discovery and how the top comes off for last second travel if needed... Please don't comment with nether as a choice. Please give reasons for your answer... Does anybody know how many areas there are to connect tubes to the discovery too?