Coca-cola seems to be trying to move in on the market of small batch, specialty sodas. This one is paradoxical mix of pure cane sugar and stevia. Stevia is a natural sugar substitute. The cane sugar is a throwback to a few decades ago when all soda used it. It's easy to find Mountain Dew and others putting out batches made with pure cane sugar. It's a little better. You can decide for yourself what kind of sweetener is better for you.
As for Coke Life, it tastes kinda like you would expect it to. It's sweet, but there is the diet taste there also. It's still Coke, which now tastes like Pepsi anyway. So, if you don't pick one of these up, you're not missing much.