What do the installers say?

Have you talked about your product with the installation teams? 

We recently bought a new washing machine. After a few days, we were terribly disappointed with its performance and exchanged it for another machine. When the installer arrived, he said, "Oh yes, we replace a lot of these. I would never recommend anything from this manufacturer."

Many firms measure Net Promoter Score, based on how your customers respond to the question "Would you recommend this to a friend?" Those who give you a 9 or 10 are known as "promoters." Those who give you less than 8 are "detractors." 

I wonder how many firms ask this question of their installation and support personnel. 

In addition to customers, most product managers chat up the product with sales people and developers. You should also get insights from customers support and progressional services folks.