Tried on a bought a pair of Smitty's lightweight version today. Just a little heavier than a poly Reebok type sweat pants. They feel great and are very light. They've put in a seam down the front to keep them looking sharp -- for pants, a good thing, but for knickers which some added, it looked stupid.
Honestly, as soon as the majority of football officials wear these pants, knickers will be a thing of the past. Can't be too soon for me. Why go through multiple pairs of white socks when a black pair will last you years even when they fade? The pants will be easier to keep clean (or at least, clean looking) and they won't fade -- I have microfiber poly shorts I've had for most of a decade that are still the same color they were when purchased and they've been washed on hot hundreds of times. I would still, however, wash these pants on cold -- warm wash/cold rinse at the hottest.