Oh yes, agree with Slinkie and Bookthief the inflatable ones are good.
I have used Handysitts at restaurants and find them infernal objects. Our local cafe had them and they acquired increasingly bloodcurdling warning notices on them and were eventually replaced. From this I infer there were accidents, though I never saw any. DS felt downright unsafe in them for a time though.
will a 2 1/2 year old need a booster? We only use a booster at home for ds (21 months) but if we are out he just uses a normal seat in a restaurant, at peoples houses, etc. If he finds it hard to reach he will kneel but mostly sits on his bum and does ok.
Yeah it's true Seona I wouldn't bother to schlepp one on holiday for 2.5 but for Grandma's house or anywhere you want decent behaviour for a relatively long meal stint a booster helps DC be comfortable.
Surprised you've managed thus far without one, though, which would make me wonder if you really have a need.