regarding bearing styles, I'm of the opinion that needle bearings are the far superior technology for headset use. Balls are great for things like hubs and bottom brackets that are constantly spinning around, but a headset does very little rotation, and the result is that road shock is transfered up the fork to the bottom headset cup and crown race in a few specific spots (where the bearings touch them.) Needle bearings spread out the force in a line rather than a point, vastly decreasing pitting while still rolling well enough to provide a smooth headset. As far as the bearings in these specific headsets go, I have no idea, but I just overhauled a needle bearing headset that has been well-abused and ill-maintained for the past 3 or 4 years that shows absolutely no signs of damage. Stronglight is generally credited for the first needle-bearing headsets, too.