I'm 56, I have ridden MTB since 1994 when I bought a Santa Cruz Tazmon, I've ridden and races most things since, way back then I could only dream of the choices available to us now but personally having owned the Levo, Shuttle (original), Simpson, Cube, SC Bullet, I much prefer the lighter version of an assisted bike as it suits my style of natural trails over bikeparks where some of the heavier options belong and are built for.There is also some kind of sliding scale of detrimental riding experiences when it comes to weight. I think sub 17.5KG introduces way too many compromises (paper thin tyres, small rotors, XC wheelsets) that provide almost no significant benefit and many disadvanteges for most riders.