I've owned this ladder (w/o trestle brackets) for several years and I can tell you from experience, it is not "light weight." That being said, it is still my go to ladder if I'm doing any kind of work from a ladder or if I'm carrying any kind of load up and down it. It is a trades-quality product. I wouldn't do any electrical work from it (for obvious reasons), but have absolutely put it thru its paces and it continues to go strong.
I use a high quality dry lubricant on the hinge points. That's the only maintenance I've ever had to do.
As far as the harbor freight knock-off goes, there is a wide void between these two ladders.
If you need a mack daddy multipurpose ladder, get this one you won't regret it.