It's defo a boys toy thing for me. The bike is far superior to myself

I just adore beautiful engineering, on anything. Be it cars, bikes, hifi, or even just a kettle.
It's not about speed for me though. It's about the sheer enjoyment. I simply love light bikes. Hacking along, being able to pop a jump over stumps and roots is great fun.
Btw, my wheels are over engineered if anything (
http://www.mavic.com/ewb_pages/v/vtt_produit_roue_crossmax_sl_disc.php?gamme=vtt) The last place I want weakness is in the wheels when I land! Light stuff is best reserved for other areas like posts, seat, bars etc, unless you don't do jumps of course. I had a go on a bmx at the weekend, which weighed more than my full size MTB, suprisingly. Although mine doesn't feel light now, it's all the others that feel damn heavy to me.
I did have an even lighter bike eight years ago. It was less useable in rough stuff though, being a hard tail trek. It had carbon tri spoke wheels and carbon frame, twist shifter, rear mech only, XTR v brakes, titanium x-lite everything. It was too light though, lacking half the strength my current ride seems to have. Good for smooth cross country but NOT a playbike by any means!