JoeyL, I am curious what do you mean by "irregular". I liked my first Ultra Stinger so much I bought a second. When you got a new reflector, did you get the entire head? I can't figur out how you could take out just the reflector.
And to answer the first question, I have an SL-20, SL-35, two each; Stingers, Ultra Stinger. I have never had a problem with any of these. We have about 40 Stingers in use where I work and I have not heard of any problems with them either.
I sure wouldn't worry about the quality of Streamlights, Surefires, or Mag-Lite's. All three are top notch in the quality department.