About the first product linked...
It is copy of a extremely popular item in Scandinavia -
the Voksi Pose
Everyone I know in Scandinavia has one and knowing a bit more about having babies in Scandinavia, you know why. People there own these
HUGE prams They look cumbersome, but there are two great reason for having one there:
1. If you don't own a car (which MANY people there don't) and need to bring baby + groceries home, they are very handy.
2. Babies take their naps outside because everyone there agrees that babies sleep better and longer in fresh air (and yes, people put listen to baby monitors and check on their little ones often

). They prams must be big enough so babies up to 2 years of age can nap comfortably in them. Oh, and they make special 'seat belts" the babies wear at all times so they don't fall out the pram and the prams are constructed never to tip over.
That's where the Voksi bag comes in. Think of Scandinavian winter - you will want a super warm and cosy sleeping bag for your baby to sleep in of course. The Voksi is so great that your baby stays warm to sleep outside even in Norway! And obviously, when you need to bring the baby in, you don't want to have to take him out of the cosy bag and expose him to the cold -- that's why the Voksi has handles!!
The Voksi was never meant to be used the way bucket seats are used in the US (the ToysRUs product seems to advertise the product as a convenient way to transport the baby!). At least, I have never seen parents in Denmark transport their babies in them like that!

The handles are just for VERY SHORT trips - from home to pram OR from pram to car, etc.
I also love how the Voksi makes the best play mat ever!
Anyway, I just had to come out of hiding and defend my Voksi. I LOVE IT, even though I have since stopped using prams and am now a babywearer...