(My wife struggled with grip shift so I'll be avoiding for the kids).
£139 for the 24" version with a quoted weight of 9.75kg looks pretty good compared with a Frog for £285 (9.2kg), although the Frog comes with mudguards and a spare set of tyres. They are obviously copying the Frog bikes as one of them is pretty much the exact same colour. Would be interesting to see how they compare in the flesh.............
I decided to take a punt and it might be as you'd expect.
I got the 20 inch version (£130 from eBay) which has a supposed weight of 8.5kg, it tops the scales at 9.5 but with hefty kick stand removed it's a little over 9 (if you discounted weight of pedals as well i think it would be there or there abouts). Seems like a lot of weight in the back wheel, i think I'll see if there's anything that can be done there to shed a bit.
Cranks are 130mm so a little longer than I'd prefer. Also bb axel could be 5-10mm shorter.
Otherwise I'm pretty happy with it, the brake levers don't really look like child specific ones but have plenty of reach adjustment and i think they'll be fine (it's his birthday in two days so it's not been ridden yet) . I think they're meant to be Pro Max it something but they're not branded at all.
I've swapped the almost slick kenda tyres for some 1.9 inch schwalbes.
I was looking at a Raleigh performance 20 for £200 and having seen the 24 inch version in a LBS i do think it would have been lighter and of slightly better quality, but for the money i cant really complain.
In summary, buying new i don't think you'd get more for your money, not as good as an isla bike but not too far from a frog.