Matt,
If you are set on a 26″ then the isla’s (IMHO) don’t make as much sense as those in the smaller wheel sizes, where it makes a much more compelling argument.
A lot of the difference is stuff like smaller cranks / small hand friendly shifters. Whilst good short term, it’s all a bit too quirky as an upgrade-able platform for me.
I looked at it, and honestly, standard SLX shifters and Avid 3s which I put on my daughters work fine and she has no problem reaching the controls.
Sure hers is heavier than the Beinn, but then it has 100mm travel rather than rigid forks, hydro brakes over Vs, 30 speed vs. 16, etc. etc.
She still managed a 50 mile charity ride on it last year, we only saw 2 other kids do that distance, and they were both on junior road bikes.
Thing is she’s out growing this frame now 18 months on, a replacement frame will be <£150, but all the parts are still worth keeping. With a child’s specific bike you’d be wanting to swap these as you go up in frame size to match. (As someone else said, kids don’t live on coal any more.. my 13y/o son is 6’1″, no way he needs “small hands” specific brakes!!! )
My advice for a 26″ kids bikes is probably opposite to what you’d do for an adult bike. Go for the best components you can, sacrificing a little on the frame, knowing in the not too distant future you will reuse them on a larger / better frame.
Si.
P.S. I might have an XS Malt frame we can do a deal on 🙂