I use the Vega Sport Performance Optimizer (that's a mouthful so I'm just going to call it Vega Sport from now on) regularly before my workouts. I love it! During my long runs I always carry a bottle on me. While I was training for my most recent half marathon, I relied on my Vega Sport to help me reach my distance goals. For a half marathon I think it's perfect. If I was doing a marathon I'd want to take something more with me, but for 21 km the Vega Sport does the trick.
In the past on race day, I've just resigned myself to the fact that I'll have to go the distance without my Vega Sport because the water stations usually serve Gatorade or some equivalent that I would never use. So, I've just taken water when needed and carried some sort of vegan gel just in case. My most recent race I decided to try something different. I'm use to carrying a bottle in my hand when I do short training runs (I really hate wearing a fuel belt for so many reasons), so I thought why not take a bottle with me with my Vega Sport mix?
I know you're not supposed to try new things on race day, but the only thing new was carrying a bottle in hand for a longer distance. I decided to use a recyclable water bottle just in case it started to distract me and I would have to toss it at one of the water stations. At the start line, I was probably the only person with a water bottle in hand, but I knew it might be needed en route. (By the way, I was running the Columbia Gorge half marathon in Oregon, which is one of the most beautiful routes I've ever run!) I carried my Vega Sport for all but 3 kms. It worked out great. I could fuel when needed and didn't need to stop at those, sometimes congested, water stations. I'll definitely make this a regular practice for the half marathon distance.