I bought this for my 7 month old little boy, even though he's nowhere near using it as a walker I wanted something that would encourage him to practice sitting, as he's so keen to be on the move he doesn't really get practice sitting for long because as soon as he's on the floor he's off trying to crawl.
I chose this one over other similar things because it looked sturdy, had good reviews and I have been very happy with a highchair from chicco.
This is perfect, and he absolutely loves it. Even at 7 months he is gets the idea of the ball going in the hole at the top and he loves all the sounds and lights, especially the two side bits. He will pull the musical side tab and when it stops pull it again straight away to start it again.
It is very well built as I expected from chicco and it feels very sturdy, I don't have any concerns about it tipping when he does reach the stage of pulling himself up and walking with it.
I like the fact that it has brakes and that it doesn't go 'backwards', only forwards.
The only downsides (and they are minor) are:
when he is sitting in front of it playing with the activity part, it is quite easy for him to pull it down ontop of him, but that has been easily rectified by either wedging the stabalisers under the sofa or other such thing, or by placing my feet on the stabilisers, since we don't leave him to play unsupervised anyway this really isn't a big issue and if he was older, (like the suggested 9 months) it may not be an issue at all.
It would be great if there was some way it could fold down for storage.
Other than those two things, which are minor, I really can't rate this high enough and the enjoyment my little boy gets from it, and will continue to get from it for months to come is more than worth it.