IMO, "mostly street" tips it in the flat tappet direction. You will give up a small amount of HP for a lot less $, less valve train wear ( in particular springs ), and less moving parts to fail. Street is all about longevity, and when you are talking about lifts and durations that you are, light is right on the street. Hughes comments on flat vs roller cams was mostly based on the larger .904 lifter that Chrysler uses - which Hughes claims their cams are based on ( "real Chrysler cams")vs other cam manufactures.