Buying scales = prepare for disappointment. lol
That said, my Five – being the versatile do it all bike it is – ranges from 28lb in marathon spec, 29lb in normal trail spec, 30lb in burlier trail spec and 32lb in DH uplift mode. Nearly all of those weight variations is down to a tyre and tube combinations (with minor spec changes) LOL. The lightest being 2.1 HRs with 1.5 tubes to 2.35 Kendas with DH tubes (500g a piece!)
I stopped agonising over grams here and there when I can drop or gain a whole pound or two based on what rubber is going on.
I too laugh at people going crazy light on supposedly burlier bikes. I got my Five down towards the 26lb mark at one point and it was rubbish! I ended up just getting fitter and dealing with the 30lb weight which seems the best weight for it and is the most fun.