Cruzbike sell theirs on several points, one of which is lack of long chain drag and the ability to use standard components, the other is the MBB allowing you to use push/pull from the upper body as well, supposedly improving climbing performance.
When you look at weight, they probably have and advantage as well - I remember the ICE B2 as heavy, also undergeared in my version, but my M5 is no lightweight either coming in at around 14.5kg naked. I could have lightened it with wheels, components, rim brakes etc but probably not by a lot.
The climbing advantage I buy, but not the "stock components" argument - everything I used was off the shelf, except chains which are just off the shelf x 3