If you had to choose... Isofix or 5 point harness?

[TexMex]

My DD (4) is getting too tall for her seat (Britax duo plus) but is not yet 15kg. I am getting in a tizz after looking at the in car safety website - it seems I can get a (very expensive) Britax 2 way elite and keep the 5 point harness for longer, but the seat is secured by a seatbelt not isofix. Or I can get a Britax kidfix sict which looks great and is isofix, but she would be secured with car seat belt which I've heard isn't great if a child is lighter? Any advise on which you'd go for?

How about looking at at stage 1-2-3 seat? something like the Britax Evolva or the Recaro young sport. Theses are both seats that have a 5point harness that can be used until 18kg and then harness is removed and it becomes a highback booster so they will be taller than a dedicated stage 1 only seat like your current one. I would go check one out 'in the flesh' first though and get your dd to sit in one and try it in your car as they tend to use quite a lot of seat belt to fit them (they are belt fit only).

I personaly would not put a child under 15kg in a booster seat and prefrably not until 18kg (which at ds3s rate will be when hes off to uni as he is 3.9yrs and only 11kg!)

I have both, and I'd say look on youtube for the crash vids- that'll help!

I use the two way in my car (long distance, lots of motorways), and the kid fix for GPs.

Hmmm I spent ages looking on you tune and they both seemed as bad as each other to be honest! I will weigh DD tomorrow and start to feed her up!!

Are you looking at the TWE forwards or rearwards facing?

vs I think the TWE shows a lot less movement!