Rating: 4 / 5
...to a 5
Using my standard GBU categorization, we have...
1. Bright light output on HIGH
2. Decent battery life on MED, and LOW
3. Nice packaging
4. Comfortable to wear (strap absorbs some sweat).
5. Good switch ergonomics.
6. Accepts Li batts.
1. Fair, at best, regulation - especially on HI (but decent on medium and lo). This "crab" is mitigated somewhat by the fact the Medium output is usually all that is necessary, even for some non-demanding path/trail walking.
UGLY??? This is one pretty boy!!!
I'd love to give this headlamp a decimal rating of just shy of 4.5. It's really that good. The main reason why I don't give the Quad a 5 rating is its very poor constant current regulation on HIGH output mode, though use of Li AA batts greatly improves that deficiency, but at a cost. There are other implementations of regulation which are better, IMO, even with alkaline batts, hence my choice to not give the Quad a 5.
However, all that said, if regulation on HIGH output is not that important to you, then the Quad would be a solid 4.9 or 4.95 (it's that good, but all things can usually be improved).