Combustion Contraption

While i was bored today i was flipping through an old issue of honda tuning, and there was an article all about b series motors, the OEM performance stuff you could use with them etc. etc. Well one part that was of particular interest to me, since im putting in my CTR cams this tues. , was that they stated when installing 'R' cams, if youre going to upgrade valve-springs to 'R's to only do so on the exhaust side, reason being that USDM type r valve springs are actually wekaer than the other b series valvesprings (the dual ones) because the USDM r's valves are lighter. Very interesting... anyone have any real world info pertaining to this?