Theses the v1 and v2 as far as the NUBM44 goes, I have not heard of anything newer than the v2 and that's what DTR sells.
The 7A75 is not as strong however it's not weak either, the 7A has a little better divergence and I run them at 4.0a which is still ok for 2 x 18650 EFest cells and I wanted to use my 2 cell battery tube with the build as the 3 cell tube I have for it did not move heat away from the driver as well.......that said I do like the 7A75, they are punchy little blue burners.
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Also I can use the DTR G2 with the 7A75 and C-lens when adding in the 3X beam expander, but when using the NUBM44 I have to use the Sanwu G2 if using the 6X c-lens pair and adding the 3X beam expander because of the slight focal length difference and the 44's enormous divergence.
If not adding the beam expander I can use the DTR G2 with the 44 and 6X pair, I only need the Sanwu G2 if adding the 3XBE in this case.