I've been using the Emilydeals replacement band for my Whoop 4.0 for about a month now, and it's been a surprisingly great experience. The soft nylon knit feels just like the original - breathable during workouts and comfortable enough to sleep in.
What really impressed me was how well the U-shaped metal frame holds the device securely. Even during my most intense CrossFit sessions, the band stays put without any slipping. The slight stretch in the fabric makes it easy to adjust for different wrist sizes throughout the day.
I ordered the navy blue color, which looks more sophisticated in person than in the product photos. While it doesn't have the WHOOP branding (which I actually prefer for a more subtle look), the quality rivals the original at nearly half the price.
The only minor issue I've noticed is that the charger connection isn't quite as seamless as with OEM bands - sometimes I need to wiggle it slightly to initiate charging. But for daily wear and tracking purposes, this band performs flawlessly.
After trying several third-party options, this is the first one that's convinced me to stop buying expensive original bands. I'll definitely be ordering more colors to match different outfits!