Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Nothing "Professional" about it.

I've just received my third defective monitor from Viewsonic. The first monitor suffered from uncorrectable vertical distoration, bent vertical grid wires, and uneven brightness. The second monitored started failing after four months of use. The new monitor has uneven brightness where half the monitor is darker than the other half. Viewsonic has lost me as a customer. The shipping cost to return them is starting to add up.