Normally love trijicon & acogs - Trijicon 2x20 mm Compact Dual Illuminated ACOG Scope

I have a number of ACOGs and love these Optics, but had a problem with the 9mm version of this scope. The Glass is awesome and the Fiber Red Dot was visible and worked great in ambient light, but the Tritium Red Dot was virtually non-existent and unusable in low light/no light conditions. Hopefully it was just a cause of a specific flawed optic, but I've never seen this before for a Trijicon Optic. Don't know if this was a specific problem with this one scope or if Trijicon didn't make the specific tritium red dot in the 9mm version of this scope large enough and/or bright enough? I'll always recommend Trijicon & ACOGs, but not so much the 9mm version of this specific optic.