He'll definitely boost marbling. Will probably improve udders and moderate milk in his daughters. Might see some 'heat' in the dispositions. Bet he'll cut frame score.
Have not seen any Prime Star calves, but used his sire, D806, for several years - very little growth in the steers, heifers were, for the most part, downsized a couple of frame scores (and 300-400 lbs) from their dams - and most are pretty danged ugly - but the ones that stayed are looking better as 5-6 year olds than they were as 2s.