Sorry, I gave the wrong information on this. The battery pods and batteries are exactly the same dimensions except the length is ~1 5/8" (41mm) shorter than the Bluefin HD pods and batteries, and therefore will be lighter. The new pods are now black anodized. The light heads themselves are almost exactly the same size and shape as the Sunray HID's, and slightly heavier, but not substantially. The HID heads are slightly buoyant in fresh water, and the LED heads are very slightly negative, but should be about neutral in salt water. Housing buoyancy adjustments should be minimal, or may not even be necessary. The LED's are very bright on high, and even medium looks brighter and whiter than the Sunray HID's. The width of the LED's beam pattern is almost exactly the same (very slightly less) as the HID's, but has more even light to the outside edges. The LED's beam is very clean and even, but being picky, it is slightly brighter near the middle, whereas the HID's are slightly darker. This is probably a good thing, as it will better highlight your subject. Now I'm dying to try them on a dive, but my favorite boat isn't doing a night dive till the 17th. I will definitely use them during a day dive on Saturday. Early conclusion, they look like keepers!
The new batteries and pods are a little heavier than the older HID's, so re-adjusting buoyancy will be necessary.
John, I got the new pods and still have my old ones, which may be for sale soon with the HID lights.
Note: On the cover of the box it has a checkbox for L&M housings, and a checkbox for Gates, Amphibico, Ikelite and Seatool housings (includes G.A.S. Adaptor Plate), so it looks like the LED's will be available to fit other housings as well.