Do you find they {headlamps} stay pretty stationary with the battery packs and all?
The Princeton Tec EOS is rock solid on my head. It doesn't really weight that much anyway. No issues with movement or flopping. The up/down angle adjustment has 'stops' to help prevent it from drooping. Works well.
Personally I don't care for headlamps that have secondary battery packs because they become difficult to handle off-head. I want them simple.