Alot will depend on where you dive. I have had UWLD lights for years. I just upgraded to the LD-40 but haven't gotten it in the water yet. I love my UWLD 26 and 35, but I joke that they're the Underwater Silt Dude. Because the beam angle is so wide you get alot of backscatter. Even in crystal clear cave if you're trying to look at a tunnel far away it doesn't have the punch to really see far away like you could with an HID. It's not saying they're bad lights at all. They're excellent and some of the brightest you will find. I can see things in caves with my UWLD that I couldn't with other lights. The wide beam angle can also lead to troublesome team signalling. If you dive regularly with someone it's a non-issue. But if I'm in the lead my UWLD needs to be on medium or low to see other people's signals effectively. Also you have to signal with the light a little differently than others so you're buddy can see what you're saying. None of those things should be deterrents, but every light has it's quirks. The UWLD 40 has a tighter beam than the others so I'm excited to compare it. I will report back.
I just bought my wife a Halcyon Focus 2.0. She borrowed one because her light died and she fell in love. She's always liked her UWLD but hated the backscatter. The Focus is an LED that performs like an HID, meaning it has a tight beam and can punch through backscatter. You can also widen the beam for video. She absolutely loves it. The big issue is the battery is odd. It's very small, but gives about 5 hours of dive time on high. We ended up getting her one on an e/o with the battery and then also bought a big light monkey 30ampH dual outlet canister so she can run her heated vest and light at the same time and never worry about battery. So she has the stock battery for regular dives and the LM battery for bigger dives and when heat is needed.Some people don't like that on the Halcyon when the beams it's tightest you can see the 4 LED emmiters. The reality it's a non issue because it doesn't need to be that tight. A slight widening just past full tightness and you can't see the LEDs. (They look like a cross when you see them).
All Light Monkey products are excellent and you can't go wrong with them. I personally don't like their VF (variable focus) light because I don't like the color temperature. My buddy had one and it just looked odd. I've been told that has been changed, but I would do a try before you buy and make sure what you try is the newest version.
The reality is you can't go wrong with an UWLD, LM, or Halcyon light. If you have the chance to dive multiple before you buy you should. Personally I'm not a fan of Big Blue or Dive Rite lights. DR lights never quite perform as well as the other 3 brands in my opinion. Big Blue lies about their lights output which bothers me and they're customer service isn't great (and I work 10 minutes from their showroom so I could just walk in if I wanted).
Good news is LM, UWLD, Halcyon, and Dive Rite all have the best lights in the industry (imo) and all definitely have the best customer service.
For example, I haven't tried my UWLD LD40 yet because my wife took it on a dive and it flooded in the first 10 minutes. I was never once worried because I knew Bobby would take care of it no questions asked. Come to find out his distributor sold him cord that was not the spec he ordered and led to the floods. It was immediately fixed and Bobby was overly apologetic eventhough he didn't need to be as it wasn't his fault.
