Bought two of these (one pink and one blue) for my twin grandchildren (aged exactly 3 at the time) just over six months ago. At first, they inflated well and seemed to stay firm for a couple of nights. Now they don't seem to go as firm no matter how long you inflate them for (draining the very expensive batteries) and need a further inflate prior to the next night's sleep. In addition, unless the child actually sleeps right at the top of the bed by the blow up head board (and don't move all night), they end up with their legs hanging off the end of the mattress - resulting in a very grumpy children the next morning (or worse still, them waking up and relocating to my bed resulting in me not getting much sleep)!! My grandson is of average size and weight for a 3.5 year old and his twin sister is around the size of a child about 34-36 months. The base of the bed is also very thin and it doesn't seem like there's much room between them and the floor they're lying on.
The material on the top of the bed is of reasonable quality, but you will need an extra cover on top in colder weather. The underside is made of nylon and this has parted at the seems in several places on both beds (identical places in both beds actually - down the edges by the zip).
I also found that the side bumpers don't stop them rolling out of the bed - they've managed to do this on several occasions.
The bag the beds come in are very sturdy and well made.
I had hoped the beds would last them around 18 months but this obviously isn't the case.
I did consider just buying mattresses, but this leaves storage problems, so am going to take a chance on the Tween version of the ready bed as these seem to get good reviews.