This system does appear to be more stable, and having used the gatortrail for both kids I would have probably gone for this type of system.
The problem with the gator trail is that if you corner too sharply or make a sudden move you can unbalance yourself, particularly as the coupling is attached to your saddle post which affects your centre of gravity somewhat.
Depends on how confident a rider you are, my wife was not so keen on towing our youngest, particularly on busy stretches.
One thing you have to remember with these systems is to get the front wheel height of the childs bike correct- not nice when you corner and their front wheel virtually flips you.