I was one of the first breeders in Canada to use CUP ultrasound, and do my heifers.
The data was interesting, but we saw the previous numbers affected the numbers we got more than the actual scan.
The technician was impressed that we could have bulls that scanned higher than 4% imf (choice) with less than .2 backfat.
Our heifers were similar, but had .3 or .4 backfat.
Compare this to most bulls for sale at .5-.75 backfat with 2.5-3.5% imf.
We have discontinued the ulrasound scanning because of cost, and lack of buyer interest. We continue to select A.I sires on high accuracy traits including above average imf rea and below average fat cover, if possible. Sometimes we will sacrifice one of the carcass traits before we will sacrifice traits like bw or gain.