The LED lottery is still in affect, as my new L2D I had was no brighter than the original L1D I had.... Just to keep that in mind.
Anywho, my 2 cents on 2xAA lights. They are too long to EDC (for me at least). The 1AA nitecore is awesome, and I love the multi levels and everything about it (would love to see the ramp in right direction from low/high put into the new ones too, are they?). With a clip it's a perfect EDC that gives you uber low which I thought I'd never use but I actually do when reading stuff at night.
But for a 2xAA light it's a bit too big to EDC. Only to carry when going in the woods, or what not. And if I'm going to carry something that isn't my EDC, I want it to be a big improvement (in power, or runtime) over my EDC, and will not care about ultra low light levels. For that reason, I would love the D20 if it were a bit of a different animal. Keep the PD design, but make it 2 mode only. Twisting/pushing further to go into high would be great, (much like the original PDs). 2 modes, turbo, and normal. Normal could be long runtime (no crazy 3 weeks needed here!) but bright enough for most everything like 60 lumens. Then turbo would be full tilt for when you need it. And since the light is not edc, and pretty long, might as well make the head pretty large. I wouldn't mind a 27-30mm reflector in a light like this. Give it some throw. Make it powerfull and 2 modes. Make it a ultility light not an EDC that has to cover all situations. Going into the woods you want a throwing light with decent run time, and 2xAA cree can do that without being as big as a C or D sized light. And if you make it 2 levels, you can make it constant current controled for more runtime. A torch like this in the same HA and PD design would rock.
To me the long narrow 2xAA lights don't fit in one category fully. They need bigger heads to throw and put them in the utility/etc category, as they are bit too large for EDC, but don't throw much to put them in the larger light category. Can't we have a middle size between EDC and C/D sized lights in AA flavor? CR123a lights fill this section with some having large reflector heads, but not many 2xAA lights.
My 2 cents.