I used a Tange Levin once, and it became brinnelled after only about one year of use. It was installed by a bike shop that I've used for a long time and trust.

In contrast, I have had excellent performance and durability from Velo-Orange, Chris King and Campy Record headsets. The VO headsets are a tremendous value, IMHO, and they have sealed bearings, which I prefer. I have heard many recommendations over the years for Stronglight headsets, but are they still in production? I tried to purchase one once and had a hard time finding except old used ones on eBay.