3 yo DD2 managed fine on the bench, just had to keep reminding her not to lean back! Fantastic kids menus, makes a change to all the other crap the little ones get offered in other places. Always found it hard to comprehend that we go out to eat great food and they usually get offered rubbish. Love it in Spain because they get smaller portions of our food, much more exciting.
I thought the food on the kids menu at wagamama was rubbish actually... plastic noodles and horrible chicken with yucky sauce.... I would definitely order enough of the adult food to be able to feed kids with...
I'd advise against using the chopsticks that come with the kids meals - we took DD1 when she was 4, and because she couldn't get close enough to the table, every time she picked something up with her little kiddy-chopsticks, it fell onto the floor
DS loves it, but what we do now is to order him a bowl of plain noodles (2.50 for a huge bowl), and then give him bits out of ours, plus the huge amount of edamame and dumplings he packs away. I don't like the childrens menu, and he's not trustworthy with a bowl of ramen yet.
Inspired by this thread, I went on Friday with DH, DB and DD2 (18 months) and we all had a good time! She was so excited to be out without her big sister, and they brought her Postman Pat colouring to scribble over!