I got my son a Cube260 for his 9th birthday as an upgrade from a Ridgeback MX20, even though I’m fairly committed to Islabikes. It is fairly heavy, but no more so than other non-Islabike kids cycles, and its got upgradeable features like disk mounts etc. He didn’t want the Beinn 26 and there’s no point in getting them something they don’t like.
It’s good him having a bike with directly swappable parts and tyres with one of my bikes – he has a selection of road and off-road tyres for it simply because they are the ones I have lying around. Crudcatchers also can be shared between us.
Luckily he loves it – we’ve done Cannock Chase a few times on it and plan to take a trip to Cwmcarn soon.
Hope this helps