I've got a HAB...and after taking a little while to get used to it, just love it.
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Regarding the material becoming too stretchy as they get older, we haven't had that problem...but he's only 6 months.
I used the HAB for my DD up until she was about 18 mths old (not all the time, but when we went shopping, etc) and it's never stretched out. She loved it, even up until then.