Last time I raised a pair of show steers (5 years ago now) I averaged 3.77lbs on one and under 2 on the other. Same pen/same feedpan over a period of 6 months. One was 600lbs starting out the other was 900, respectively (4 months difference in age as well). The 3.77 steer won grand champion ADG and weighed 1290 at just under 13 months of age.
On our feedlot steers right now, we're aiming for an average of 3 without implants or supplements, but we also aren't feeding all the way to Prime or even high choice.