According to my wheel vendor the 9173s weigh approximately 29 lbs. Also according to him other SRT wheels are 4 to 5 pounds heavier with the Goliath's being the heaviest. My guess is that 38 lbs isn't out of the question for the Goliath wheels. Unfortunately I didn't weigh my 9173s before having the tires mounted on them, but I can say handling both the 9173s with the 295/45/20 tires and my OEM 20 x 8 wheels with 265/50/20 tires that the SRT wheels and tires don't weigh any more than the OEM R/T wheels and tires do. In fact they may weigh slightly less.
In my opinion 23 pounds is very light for a 20 x 10 wheel, even if it is forged. I've had several sets of 18" and 19" forged wheels on the Z cars I've owned and those ranged from 19 pounds to 26 pounds depending on the size and width.