HID's are so yesterday, LED is where you want to go as others have said.
The Harley Daymakers are from what I can gather pretty much these
http://www.jwspeaker.com/products/headlights/model-8630-575-round-led-high-low-headlight which come with 4-year warranties instead of 1 (and no "Harley-Davidson" logo...)
Personally I'm getting the Truck-lite Phase 7 7-inch, because the Daymakers / JW Speaker ones are too directional - going down the road they're great, but in the twisties or when taking curves from what I gather they fire right into the road or out into space, not forward. LED light that's projected is extremely directional, there's not a lot of spill. But there's no 5.75 inch Truck-lite.