Bike the First: 19.5 lbs (or so), with pedals and without me/backpack. This is my do-everything-other-than-singletrack bike. It's lightish because a) I like lightish bikes and b) it doubles up, among other things, as my medium/long distance road bike.
Bike the Second (former commuter, now restored to mtb duties): 25 lbs (or so), with pedals and without me/backpack.

While riding, no I cannot tell the difference in weight. When lifting it up, yes.