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Title: Sport top vs. loop top
Review: Having used both tops, I think the sport top is the way to go. Why? It's more flexible. Use your thumb to press down on the release to allow sucking the drink from the bottle. That allows one-handed drinking from, say, a bike. Or, if you need to guzzle a lot of water, uncrew the sport top as you would with the loop top. With the sport top, it's easier to screw and unscrew because there's more for your hand to work with, IMO. Hope that helps.
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