Went out of a shakedown weekend backpack before the JMT and wanted to try this out. Out of the packaging felt like nice quality and put onto a 20oz smart water bottle and felt very secure. Would not leak when inverted, or even with an extreme amount of pressure. The bite aspect takes some getting used to, and no matter the position or bite pressure the flow is extremely slow, which if you take tiny sips while at a low HR might be fine. If you are parched and wanting a bit gulp, will run out of breathe before refreshed.
I found myself simply removing the cap to take a drink which defeats the purpose of such a nifty valve.
Hey Franklin! Thanks for taking the time to leave a review. We did want to give you a heads up that the BiteValves are not designed to work with hard sided bottles like Smartwater bottles, which may be why you're experiencing flow issues. Since the BiteValve works through suction and are airtight, they are designed to work with containers that can collapse down as liquid is consumed - we specifically designed them to work with our Vesicas and Hydriams.