Here is a quick run down.
The UL Super Stretch Down Hugger line(800 Down, heavier but more roomy) has been combined with the UL Spiral Down Hugger Line (800 down, lighter but less room) into the UL Super Spiral Down Hugger line (takes breath). The new line is slightly heavier than the UL Spiral DH line but has more stretchy room.
They did away with the UL Super Stretch Down hugger line all together (which is why its hard to find now) and kept making some select UL Spiral DH bags, presumably because they won so many awards (Doesn't look good to cancel an award winning line and come out with a new Heavier line).
Unfortunately it looks like they have done away with the #2's #4's and #7's with the new line. Too bad too, because a UL Super Spiral DH #2 would theoretically weigh only 26 oz ,same as a Sierra Designs Nitro 30, but with 14 oz of 800 down, I am a cold sleeper despite all this fat that's supposed to keep me warm :).