I know how you all feel about show steers but I think you can throw them into this discussion since it is all about how you feed them (ok plus hair).
In the past 10 years we have fed Angus, Main/Angus, Main/Sim/Angus, Shorthorn, Main/Sim/Chi/Angus, and last but not least Main/SH/Chi/Sim/Angus. We select our calves for the end product, Fat Steers, not fat 8 weights.
We start them on feed as soon as we can, feeding 2 to 3 percent of their body weight, a Grower/Developer feed until they hit 1000 pounds and then we put them on a Finisher ration.
The sooner you get a calf on feed the better chance you have on getting good marbling on them, some marble better than others but we got marbling on them all.
We were finishing these calves out at 16 to 17 months anywhere from 1240 to 1450 pounds. Once they had smooth cover over the ribs and some fat developing on the tail head they were done.
My grand father was a dairyman, he fed out Holstein/Angus calves, fed them dairy ration the entire time, they were 24 months old or better when he processed them, the meat was excellent just took 6 to 8 months longer to get them where they needed to be.
Pick the right calf, feed it right, and wait until it is done. Shooting for a weight is were I think you run into problems, some finish at 1100 pounds other finish at 1400, feed them until their finished and you will like your end product more.
It may cost a little more but since you are the one eating it, aren't you worth it?
Here is one we raised