FIT of 17670 in Q123-2
I have no problems fitting AW black label protected 17670, though the fit is snug. This is the only way I power my Q123-2, except in emergencies I will resort to CR123 primaries, if need be. Clip removed as well.
CLIP on Q123
In comparing the clipless Q123 to the Q123 with permanent clip, I would only choose the clipless version. For me the clip is a hinderance and in the way. Unless you REALLY MUST HAVE A CLIP, I would suggest a clipless version, if you want the Q123. Or just order the AA and a Q123 tube as an accessory. Though the Quark clip is very heavy duty and strong, I find it just in the way. Of course, I tend to remove clips on most of my lights anyway. Fortunately with the QAA, Q123-2, and QAA-2 you can use or remove the clip as desired. You don't have this option with the Q123 which has either no clip or a permanent clip.
Q123-2 HEAD with AA-2 Tube with TWO 14500 cells
Yes, I've done this and it works fine.