[bobcowan]

About two years ago Popular Hot Rodding did a test. They compared three grinds of flat tappet vs roller. Mild, moderate, and wild. Each cam was an off the shelf Comp Cams roller vs. flat grind, with as close to the same specs as you could get. In the first two tests, the power curves looked pretty much the same, a few slight variances, but not much. Once the durations got above about 260*'ish, the roller started to show it's advantage.

The bottom line was that it wasn't worth the extra expense of converting to a roller unless you're running something fairly wild.

I like PHR. They're more technical than the other mags, show more advanced equipment tests, and seem to design their tests better to show a true comparison. They actually use engine dynos and spintrons. Just look at last months issue. There's an excellent study comparing solid vs. hydraulic.