While every unit will eventually malfunction, some are more prone than others because of their design. Poor maintenance also contributes to the problem. For example, cutters and peelers may have sticker adhesive buildup if they are not cleaned regularly. Label positioning and print head settings must also be optimized to prevent paper jamming.
As to which printers are prone to logjams, customers report more of them with Rollo, Brother and Dymo units than others. However, in our experience, good maintenance, no matter what equipment, keeps us from frequently encountering such issues.