Again, its fine.
I use mine 100% as a head lamp, with the band doubled through the holder it is just fine. Ive worn it skiing, hiking, biking, working all fine. I havent extensively "ran" with it, though.
I think the best upgrade for it would simply be swaping the head band out for another companys, mammut, bd, petzl ect. The matieral of the actual head band itself is the only problem there is with the H600.
I absolutely love mine and still reccomend it.