Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great Heat, Poor Life

Pros - This product heats up fast all over and provides plenty of heat and has a small price tag.Cons - It does not have a high back and being 6 ft tall, it occasionally shifted down a little & the top edge was uncomfortable under my shouldblades. It only lasted 4 months. Having a weak back, I tend to squirm and the shoulderblade issue made me shift more. I'm also 115 lbs which adds more force on the wires. Being an engineer, I found the broken wire and repaired it only to have it fail 2 weeks later. I thought the wire size was extremely small (have never seen any other brands though) which would tend to fatique faster with movment.If you're smaller & don't squirm, this could last a while for you. I need one that's more heavy duty.