Yes, it's our major business here.
Thus, if a dairy farm is crossing their Holsteins with a beef bull/semen, they are selling all calves out, including heifers. They usually breed their best milking cows with dairy semen for replacements, so don't expect the beef crosses to be with greatest milking genetics and/or feed efficiency. When we get heifers, our most profit is when we keep them and make 3-way cross: angus x holstein heifer terminal bred to limo.
As for the bull calves - if you get them in summer/fall, you could get through the winter with much less feed, they are ok even with straw and just some hay and grain. Don't expect winter weight gains though. Then feed them on grass untill the fall and you get some 500# and more. The winter/spring crop is not worth the effort and we usually ship them for veal at 6-7months old.
The most problem with dairies is they dont have one calving season and you have to deal with calves at many different ages at one time. So, if you are going on large scale operation, you would need much more labor force than with beef cattle.
As for the profit - if you have access to beef seedstock and the initial funds for getting a beef herd, don't mess with the dairy crosses.
Just my experience.