Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Durability is the only problem

After 11 months my Harmony 520 stopped. All but Activity, Device and Help keys seems to be dead. Logitech service support was a charm, and I receive a Harmony 510 to replace the defective 520 in Rio de Janeiro, all taxes paid (Harmony 520 model was discontinued). So, I recommend to buy another model (Harmony 510) and/or to buy with an extended warranty.