I've done it. It worked fairly well. I hate the smell of basting spray, and I've found that it messes up my lungs, so I don't use it much any more.
I also press my quilt tops on the design wall -- since mine is made with insulation panels covered with felt, it can take the heat of the iron just fine. I get the best press doing it this way, specially on a large piece with lots of seams. I start by ironing the back with attention to the direction of the seams, then turn it over and get it nice and flat on the front.
RST