Honestly I would consider the 9400 closer to the Aria/Crescendo feature wise. If you were going to choose between that it would be a touch choice but the 9400 is definitely better than the soprano feature wise. I have the brother version of the babylock unity which has all the features of the crescendo and aria and I truly love my baby but if I were to have a 2nd machine the 9400 would be my first choice. It is the first machine to turn my head since owning my dreamweaver. I would look at the babylock crescendo if you really like the 9400 as it truly is amazing in its own right. The dual feed on the crescendo is what really makes the machine IMHO. the piecing on the 9400 is what makes it special, they really have very neat features unique to only them