270bdl, IMR7828sc should certainly be a worthwhile improvement and addition, as the improved loading density will certainly enable you to get more velocity in situations where the regular 7828 achieves 100% loading density at less than maximum pressure.
I have tried the regular IMR 7828 in a variety of cases and with the heavier bullets it usually gives the highest velocity. However, on the down side, I have found that it is temperature sensitive and very spikey around maximum pressure, and for this reason I don't use it in my field loads.
To complete their line of powders I would like to see them give IMR 4831 the sc treatment, and also add another short cut extruded powder which is slower than IMR 7828, and a little slower than Re 25, H1000, and Viht N170. Regards, Brian.