The biggest issue I have with this product is that the instructions are not detailed enough. I would go so far as to call them vague.  This is not unusual but when they are this poor there is usually companion video that has more detail. The videos I have seen are almost as poor as the written instructions. The heating element and power cords are intertwined and under the carriage of the base making them hard to see let alone connect. 
Once I get a few hours to deconstruct the chair and make another run at deciphering this project I can honestly tell you how I rate the chair.