UPDATE (2/23): I am upgrading it to 4 stars thanks to one of the comments made to my review. We are currently using it with our second son (11 months) and it works just like new. The play panel still freezes, so we don't really use this feature, hence 4 stars instead of 5.
When I first got this walker for my little one he was 9 months old and just started pulling him self up and walking around the crib. I thought these were signs that he is ready to start walking so I got him this walker. Unfortunately his moves were still very uncoordinated and he kept falling with the walker. At that point the walker was still very unsafe for him so I put it away. I took it out when he was 11 months and to my surprise he did great, no more falling at all. He was able to use it immediately so I believe no walker will work when the baby is not ready yet. I'm giving this walker 3 stars for two reasons. First I think the name is a bit misleading as I don't think this is a good product to learn how to stand up so "Sit-to-Stand Learning" is a bit misleading. I do however think that if a baby learned how to stand up properly this becomes a great walker. The second reason is that the play panel freezes all the time and is very annoying, so we don't even turn it on anymore and use it only as a walker.