I have just installed a set, and yes they are heavy. By comparison, I have black widow ones in my Triton, and these are every bit as well made, with the exception perhaps of a few sharp edges. I have to say, that at about $1000 saving, its a small complaint
With regard the fridge slide, it has a front steel brace front and rear under the base board. I probably will strengthen the slide lock, its a bit light on.
My only concern is the way the side wings fit across the jack and wheel tool "port" is. Either I will somehow modify that access or have to relocate the jack etc.