Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Slow Breaking In

I have purchased Propet for about 15 years. Recently the brand changed styles, these are not nearly as comfortable as the Propet's I was wearing about 4 years ago. I am having a hard time breaking these in. I work on my feet all day, and so far I can't wear these a full day yet. I think I will have to buy some other brand. They are very stiff.