Do a search here on the Darkbuster HID, and you'll find a few of us that like it. The reason you don't hear that much about it is that is not sold through common dive shops or marketed as well as UK or the high-end models like Salvo (Subatoys.com has them). Maybe that is why it is so low cost for such a great light, and also why many people won't buy it - percieved (low) value due to low cost, and unfamiliarity (besides not being a canister).
But I can assure you it is a well made light - been diving with it for over a year. I've seen the Darkbusters used as video lights on several underwater TV documentarys as well as the Jessica Alba movie "Into the Blue", so professionals obviously like them.
I imagine that the Darkbuster is heavier than the UK cannon, but not by much.
I guess it really comes down to how much light you want, while paying the same. I think that the Cannon is slightly less expensive, but does not have Lithium Ion rechargable batts, so you will spend on new batteries what you would save.
I've done dark wrecks in low vis, and night dives in Hawaii with 80 ft vis, and it is not too much light in my opinion as some would argue. I use a video diffuser and still get better penetration than other lights in clear water, without scaring fish.
To me its all about getting the most light for the least money, regardless of weight and size. I never would own a light beyond 400 lumens if it weren't for the Darkbuster's low cost.
1750 Lumens is insanely bright, and very useful (and fun!) above water as well. No light can touch that brightness until you spend well over a grand.
