In terms of comfort, chest straps will never get a thumbs up across the board. Chest straps wrap snugly around the chest at the sternum, and if they're not tight enough, they can slide down or wiggle out of place. Repositioning them while you're in motion is tough. A bad one can chafe your skin, and they're poor at providing visual feedback because you can't see them. We tend to prefer armbands over chest straps. They're much easier to wear, you can adjust them quickly even while you're in motion, and they don't cause chafing. They often have LEDs that flash different colors depending on your heart rate zone. That's the kind of visual feedback you can't get from a chest strap alone. With chest straps, you typically have to rely on a connected tracker to see your heart rate numbers.