I have had a split roller for years now – its been really good.
Only potential problem with is depth for helmets, etc but I had my ski helmet packed in the upper section ok for a recent ski trip, and ski boots in the lower section.
It is also good for dealing with airlines that get sticky over bag weight – for instance American Airlines told me to get another bag for a return trip from Bermuda as my main bag was too heavy, so I had to buy a rucksack before return, but if I had had the split roller with me I could have just seperated them and checked in two lighter bags.
Mine is a slightly different design being older – mine has two external pockets at either end of the top section, looking at the new ones they seem slightly different.
The symmetry of mine is good, if I am going upstairs I grab the front strap on the top to lift the bag, and it is then tilted to go upstairs, and I grab the back handle to go downstairs so it tilted the other way. This is when I am also carrying a skitube.