I thought initially this was a bit expensive considering there is no power bank included. I then realized in general heated blankets are pretty expensive, and this is basically a more durable/specialized heated blanket. So I think the price is fine.
It doesn't get too warm, but that's to be expected as a power bank is only giving off 15-20 watts. You can't really change physics. Also note a 10000 mah power bank is about 38 Watt hours. If your bank's efficiency is 70%, you should expect a bit less than 2 hours on high. ((38*.7)/15).
The actual feel of it is ok. Nothing feels "nice" on skin, but this isn't really designed for direct contact anyways so it doesn't really matter
My only real complaint is I don't like it's input is USB A. I know a lot of power banks have USB A, though I really try to make everything have USB C.
Overall it works, it's light, the price is decent so I think 5 stars is reserved.