I have replaced the lights in my '73 Volvo 164E, '83 300D-T, and '86 911 turbo with Hella European Headlights combined with 55-100 bulbs and I have never had a harness burn or assembly problem. I opted not to use the 80-100 because the dazzle from the low beams at 80 watts, especially if they were missalligned, would be dangerous to others. I found that the lens pattern as well as a non sealed halogen lampule provided better lighting in each case. The high beams are nothing less than superlative.
I can only relay my experience.