What is the safest non-isofix high back booster?

[babyblabber]

Am getting some car seats for my mum's car. Quite nervous as I would consider our own car seats of a very high standard but can't afford the same again. They will only be used occasionally.

Getting britax evolva for our 2.5 year old (forward facing, eek!) but no idea what to get for our 5 year old. The isofix HBBs are just too expensive. Was thinking of the britax adventure but then read online it didn't get a great rating from which.

Any tips for me?

my older kids have all used a britax adventure seat, and we have been very happy with them, when I bought them they had a pretty good review on which, so im not sure whats changed-although that was a few years ago x

Which? don't like it because in their tests they say it subjects the child to high loads in a frontal crash situation. I'm not sure how they measure these things, but the side impact protection is good.

I don't really see how there can be that much variation in high backed boosters - they are just 'seatbelt positioners' really, with the added side impact protection for the body and head. I can only think that because the Adventure is not ISOFIX (and therefore not fixed rigidly in the car) that in the event of a crash the child has the weight of the Adventure behind it, pushing the body against the seatbelt, whereas this wouldn't happen with an ISOFIX seat that would not be able to move forward. But I'm just thinking out loud there, I'm not sure if that makes any sense!

I have two Adventures, they are fantastic value for money and a hundred times better than the Graco Junior Maxi equivalent seat (my mum has one of the Graco ones for her car). The Adventure has really deep head and body support, whereas Which? say that the back and headrest of the Graco seat is next to useless and provides hardly any side impact protection. You can see why just by comparing the two side by side, the Graco seat is really shallow.

Also the Adventure has a slim base, so it fits against modern 'sculpted' vehicle seats really well. The Graco has a wide, flat, base and wobbled all over place in our old Renault Scenic because the seats of that car sloped up at the edges. It does fit ok in my mums Toyota Verso though because her seats are quite flat.

Anyway, to get to the point - I think the Adventure will be fine for occasional use in the grandparents car. I chop and change between our Adventures and the one KidFix ISOFIX high backed booster that we have (if we have the boot seats up in the car it's not practical to have an ISOFIX booster on the seat that we need to 'flip' to allow access to the back row).

I like cybex hbb, although ours is oldish now and the prices have gone way up. We also have a joie trillo, which is a really good seat for the price imo. We also have a selection cheapo ones - a graco, an adventure, a halfords essential hbb. The halfords one is particularly useful as the sip is deeper than the graco and it's narrower than that and the adventure so fits in smaller spaces than any if the others. I must admit I mainly view them as a belt positioner though, I don't hold too much faith in their side impact protection generally due to the need for the child to be optimally positioned to benefit from it.

Thanks girls, interesting points. Am a bit of a nervous nelly and think I just need to get over the fact it won't be isofix!