I use one every 45 minutes when biking 2-4 times a week an average of 30-50 miles. I'm by no means a triathlete but, this gets rid of that "monkey on my back" aka sluggish feeling. It's quick, easy to use while pedaling away and is not gritty with a decent taste.
I really love the way this stuff works. It seems to give me energy almost instantly. The Gu brand is the only gel pack that doesn't seem like it's just sitting in my stomach. This flavor has caffeine which I think helps me out while I'm doing long rides or 24 hour races.