As long as your not expecting top notch quality then first impressions for a newborn plus sibling pushchair are excellent.
The baby can lie flat facing you in the top seat, loads of room for larger babies, no extra equipment needed, the liner that comes with seems comfy enough (plus there are footmuffs included too) at the same time the toddler can sit bolt upright in the lower seat with ample space and a perfectly reasonable view. Both children are visible (unless the toddler fancies having their hood up) and audible, which is nice as usually the toddler is further forward thus harder to converse with. This is the best of both worlds as not only can you see and hear them it's also easier to push with the weight of the toddler over the back wheels.
The push is okay, acceptable (the other double I have in my house right now is a Peach Blossom one, so a direct comparison to that isn't really right somehow). You can certainly push and steer easily with one hand on flat surfaces. Cambered pavements require more work and two hands. We don't have many hills with which to test that but it's a heavy buggy so I guess that it would be.. heavy.
I could see this being a great option for those who will only need a double for a relatively short time and thus want it to be suitable for newborn and toddler, newborn and older baby and probaby not much beyond that. Once you go beyond that point there are certainly better options for 2 toddlers, this is all about the newborn toddler combo IMHO.
Now... as long as it doesn't break....