The Mammut Smart Alpine is one of the more established models within the field of passive assisted locking, or 'hybrid', belay devices. Although it doesn't look like it, the braking mechanism is based off of the classic tube design but with some modifications to give it stronger initial bite. In many belay situations it can catch a fall by itself. Our testers complained, however, because a resting climber's weight would slowly pull rope through, requiring them to use extra hand strength that other assisted braking options didn't. We were impressed with its smooth auto-block friction, the lowest of any two strand device. Its handling in other areas, particularly rappelling, is subpar.
Overall we consider the Smart Alpine an affordable, lightweight alternative to mechanical assisted braking models. Within this niche though, the Edelrid Mega Jul performs similarly well but at less weight and cost.