Definitely a product that does what it says. It's taken me through an ironman and L'etape du Tour without needing to worry about gels/food. Couldn't ask for more.
Only thing to watch out for is if the weather is extremely hot and you naturally sweat heavily then additional salt tabs / electrolytes might be needed. Tailwind can you produce a booster tab to chuck in as well please?
Overall though it's almost perfect.