I have a q40, surge, and a shockwave. Have been using them for 2 yrs now with no problems due to construction or design. The surge and 40 leaked once due to my failure to lube the o-rings after cleaning. And once a bad batch of batteries (picked em up cheap instead of paying for the duracells) got milky in them. Cleaned, dried, and put dura's in and had no problems since. Good to hear that they stand behind them tho for future reference.