Jeremy, there is no visible brand name or model on my existing headlamp. By comparison to a known 100 lumen beam, it is about the same brightness. Loaded with 3xAAA and the head strap, it adds up to 3 ounces.
I've looked up each of the lights mentioned here, and few are described as shipping with a head strap. Or, if they do, they exclude the weight of the head strap, so I don't really know what the total adds up to. If they do describe the weight of the head strap, then they total over 3 ounces. Various reviews shows what ships with the main product, and if there is no head strap shown, then there is no head strap.
Questionable reliability? No.
Candlepower Forums. Yes, I've looked through there, but their information is not sorted. It seems to be a lot of flashlight geeks chatting.
So far, the nearest I've gotten is the upgraded iTP A3 EOS (flashlight) and a separate head strap which I am still seeking. Of course that leaves it hanging over one ear, whereas a proper headlamp should be smack in the middle of my forehead. If the head strap is too skinny, it is uncomfortable, so I may have to explore MYOG straps. I have one head strap (too heavy), but it must be 15 years old, and it is on one of the earliest 3xAA LED flashlights that ever came out.
On one long hike that I do annually, I use about three hours of headlamp, but often I take it off my head and hold the light closer to my feet so that I can see trail obstacles better. But for backpacking, it is used mostly with the head strap, and that counts in my base weight of gear. My base weight is about 11 pounds counting a bear canister, so any more ounces to be lost will be tough.