I don't know about the Cadillac Al... I have a Randolph front rest and the knobs adjust precise and flawlessly. Zero backlash. You can buy it with or without a top cradle.The Loh rests are the Cadillac of knob style rests. I've got one with two tops...a 2 1/4" for the Hunter gun and a 3" for the Varmint class gun.
They rarely come up for sale. This thread is from two years ago....if you're interested in one, you might try a 'Wanted' add in the Buy/Sell section. They're out there.-Al