I finally got to use my C8 eLED Plus this weekend, and I have to say it did a great job. It was really handy having the 2 brightness settings, in some areas another dive would kick up some sediment and the 10-watt mode would just have so much back scatter you couldn't see (like in fog with highbeams), the 5-watt did a better job of not blinding me with the back scatter.
In comparison to other lights, there was an incandesant Princetontec light (c8 equiv), a UK C8 LED, a UK Light Cannon 10W HID, and a Sartek 10W canister.
eLED Plus vs:
Sartek 10W HID canister - Sartek was brighter, but better be for the price difference...but they also had issues with the connector on it a few times.
Princetontec - no comparison, it was so dim and yellow in comparison that the guy using it was heading to the shop to get the eLED Plus this week.
UK C8 LED - it seemed far dimmer than it should be, it is likely the batteries needed replaced...but if they were fresh with that 'brightness', then I would compare it to looking at the moon (non-plus) vs looking at the sun (plus).
UK LightCannon HID - the LC (light cannon) was moderately brighter, but not by an extreme margin...it was definately more blue in color which can make it seem brighter. Would I buy the LC instead? I don't think so, the durability of the eLED with a very good light output is enough to use it as my primary. When I go HID I will go canister.
Hope this helps anyone that is looking. Instead of buying the UK rechargeable kit, I ordered 8 x 6000mAh C batteries and a charger for the same price, or less. During my test, I gave up after ~6-hours of burn time. I figure I can now pickup just the batteries for my spare light, and I can use the charger for the batteries for strobes and flashes.