Booster seats at table - how old?

[maldivemoment]

Our little one is now 2 and my folks were thinking of replacing the high chair with a booster seat - you know the kind that attach to a normal dining chair? - as they think he is getting a bit big for the good 'ol Ikea high chair. (Should add this is for when our little one is at Grandparent's house.)
I thought booster seats were exactly the same as a high chair but just took up less room. My mum seems to think they are the next stage between high chair and normal chair?

So, do we ditch the highchair and get a booster, or stick with the high chair?

Thank you in advance

If your DC is happy in a high chair, why spend the extra money?

Our 2 both rejected high chair about 18 months and insisted on sitting/kneeling on an adult chair, even if their chins were practically on the table at times!

My ds has used the booster seat at the table since he was 9 months old as we don't have room for the highchair (it's now at MILs).

I didn't really see any difference at first but now the good news is that he is very good sitting on a normal chair on his own at 15 months but the bad news is that he's discovered how to push the chair backwards so it is balancing on the two back feet so now most meals are on the sofa picnics on the living room floor...

Thank you BC & M. Think I will stick with the highchair!

we used a cheap booster seat at the table from about 18 months - took up less space than a highchair and they could sit right at the table like everyone else. We used this one