Hey there,
I am new BB member,
My DD was in the Amby until 9 months as we were moving interstate and didn't want to buy a cot before the move. She learnt to crawl at 7months. I think it would be really hard for a littlie to get out as it just moves when they move. We never doubted the safety but for the last week or two she seemed annoyed that she was stuck in there and I wanted her to be able to play in a cot.
My DS is 6 weeks old and in the Amby although he vomits a lot when he lays on his back so it looks like it might not be the right bed for him. Which is soooo sad, I LOVE it, so easy to settle them, you don't really even have to wake up.
Hope that helps