A few months ago I ordered a set of Denali D-2 (with Twisted Throttle marking on the bezel) from A&S. One of the two in the set was DOA and due to considerable difficulty (impossibility actually, caused by staff changes at A&S and shipment of an incorrect item initially from TT, then a poor fit of what should have been a proper lens) of getting an identical replacement- I ended up swapping out a D2 for what I expected to be an identical Vision X SP-110 I had in the garage.

The swap used the original D2 harness installed to run at full voltage all the time- without the dimmer function.

I was amazed to see that the VisionX lamp was more the twice as bright as the D2- a huge and extremely obvious difference.

The lamps look identical and are both apparently sourced from the same Korean maker. According to the folks at TT, there have been several variants of the D2. Internal examination confirmed that the D2 I had had a different LED than the VisionX SP-110. I do not know if all the D2 variants use the same LED or whether the latest ones are upgraded beyond what was installed in the set I purchaased. I do know that the labelling of the items from both makers provides no basis for distinguishing- ideally the type of LED and proven rated output should both be on the packaging info so customers have all required info.

After looking at the output, I decided to simply scrap both D2 lamps and use them for parts Lens, bezel, body, etc), to take advantage of the far brighter VisionX lamps I also had (which had originally been planned for install on a different bike).

I cannot comment yet on whether the VisionX lamps I installed wil have a typical LED lifespan- that will take a few years- but I have been using another set of identical VisionX lamps for a couple years with no failures.

A comment on the wiring harness provided by VisionX and TT. The TT harness uses metripack waterproof connectors and fairly heavy, well loomed wire. The VisionX harness uses Deutsch waterproof connectors and is a bit more flexible. The TT harness switch is a motorcycle type waterproof, lit, pushbutton while the VisionX switch is a waterproof unlit toggle which I consider inferior. Either harness works and the VisionX one takes a little less space. Because I have a supply of both types of connectors, I typically will cut and re-terminate at least some parts of the harness to eliminate some of the excess wire they always have. In this case, I removed a couple metripaks from the TT harness I had installed (before I tripped on the dead lamp originally supplied) and replaced them with Deutsch connector to match what was installed on the VisionX lamps.