Easy integration with AWS, it was easy as pie! No need of any manual effort or complex configuration required at all; everything is done through wizards/automated procedures which make things very simple when compared against other products in this space (like EMC VPM).
There could be some minor improvements but nothing much serious from my side that I can think about right now after using their product since last 4 months - so far no complaints whatsoever!! Very good tool if you are looking out an automation solution where your application needs regular migrations between EC2 instances within same region while not having too many dependencies outside its environment like S3 buckets etc..