After testing out the Princeton Tec Predator Pro headlamp, it is now by far my favorite and most valuable asset in after-dark bloodtrailing. The Predator Pro is a bit of a battery hog, so I use the Princeton Tec Aurora for smaller tasks like finding my way in the woods, etc. But for a bright, convenient bloodtrailing light, I've not found anything better than the Predator Pro.
It holds 4 batteries and has an ultra bright light that stays very bright for at least 3-4 hours of actual usage. The head strap fits over the crown of your head and on both sides of your head. It is a cinch to take on and off. The light is activated by turning the bulb housing to one side. It is turned off by turning it back the other direction.
I've used a lot of different lights to bloodtrail animals. Flashlights, propane lanterns, etc. In my opinion none are as bright and as easy as the Predator Pro headlamp. One of the great things about it is that it leaves my hands free to look "up-close" for blood sign on the ground. The angle of the bulb also adjusts from looking straight forward to looking straight down. That was very helpful to me, as sometimes my face was literally inches from the ground looking for blood sign.
The Predator Pro is a very sturdy unit and I have never had any problems with it on that count. The fact that it's waterproof to 2000 feet should tell you how sturdy it is. I didn't test it out under water at all (I didn't have many underwater blood trails last hunting season), but I'll take their word for it.
The only thing I don't like about the Predator Pro is that it is somewhat of a battery hog. It's a trade-off, though, that I'm willing to accept to get that ultra bright light.
I recommend the Predator Pro highly to all hunters.
Sturdy, comfortable, hands-free, easy operation, BRIGHT
Uses batteries somewhat quickly