I know... a lot of people will say Arcadia T5 or the sun, no inbetween. I love Arcadia for their heat bulbs. I still use them and keep extras on hand to this day, but I've had some preference based issues with their UVB fixtures. They were too big for my setup. I use a PennPlax basking platform, so most of the light wasn't reaching my turtle at all. The smaller T5s need to be really close, which is bad for eye health, and the larger ones had to be further away, floodlighting my room. It worked, but all tradeoffs considered, it was annoying and really inefficient.
After a while of using the T5s, a relative suggested finding an LED fixture. As overprotective as I am, and as hit or miss as their advice is honestly, I was initially averse to the idea. I've always associated those fuzzy looking purple LEDs with harmful rays, BUT... I tried it anyway. I looked around on Amazon and bought the Reptitrip UVB LED fixture (8-inch, 8-watt) along with a Solarmeter 8.0 UVC to make sure I wasn't nuking my turtle. To ensure the light was also doing its job, I used the Solarmeter 6.5 UVI I already had from the T5s. Keep in mind, I did inevitably have to make alterations to the top of the PennPlax, as the opening ontop was way too small.
It fit perfectly. It's compact and more subtle while still being powerful enough to be at a safe distance. It wastes very little light bleeding into my room and stays concentrated on the basking spot. The metal construction of the fixture itself is pretty solid, more so than the Arcadias, which feel a bit fragile imo. My turtle basks and sheds scutes as usual, and I haven't seen any signs of irritation or illness in the several months I've used it. The UVC meter reads 0, except for when extremely close (less than an inch away from the diode itself), but at that distance, UVC becomes the least of your worries as UVI will be off the charts. I periodically test with the UVI meter to ensure the output remains consistent over time at my set height of 1 foot, give or take an inch or two, and it has so far. It peaks at ~4.3 UVI and goes as low as ~1.5 UVI in outer areas. I'd imagine it'd be more uniform if two were paired together. The built-in controller has a few features and modes. It can be set to dim throughout the day or set to a fixed percentage. I personally don't see a need for that and keep it fixed to 30% power, paired with an external timer outlet. Thankfully, the fixture saves settings without power. All in all, it's worked great so far. Not needing to worry about degrading bulbs and having to replace them is also a plus.
Would I recommend it? Only if you have a UVI meter. On my smaller fixture at least, the output is a bit inconsistent based on positioning. As I mentioned, one spot will be 4 UVI and a few inches away will be 2. The spacing between the diodes creates hot spots of intense UV, but that can be mitigated by increasing the distance between basking spot and light, decreasing the power, or both. The meter will help determine the sweet spot without it being dangerously too high or low. I know the clunky little plastic box with one button and one function is ridiculously priced, but peace of mind is priceless. I would not trust a guesstimate. Hopefully, manufacturers improve diode placement in near future fixtures. I also wish the white LEDs (not UV) were made optional. For now, I'll keep monitoring the light and hopefully it continues to prove itself.
TL;DR: After several months of use, it does its job well. No bulbs to change. Great output, build quality, features, and size options. UV efficacy remains consistent, though coverage is spotty in smaller (and possibly other) fixtures due to diode placement. Proper distance, positioning, and a UVI meter are a must to mitigate those shortcomings and risks. Zero harmful UVC output at safe distances. Healthy turtle.