We have it now for about two months and I can say that it was a very good purchase. It is not too wide so as to take up unnecessary space (we have 2 small seats in the back of a city car and I sit in the middle), but at the same time it gives a sense of safety. With the isofix, it is easily, quickly, and securely installed.
In terms of sleep, like all seats in this category, it is a bit difficult, but if you find the right position for the child, they do not easily fall and their head is supported. If needed, you can use a cushion.
Regarding the strap that someone mentioned... you need to pay attention to it, because it is secured with the car's seatbelt. It is not an issue with the seat itself.
All in all, I recommend it