I have always told people outside our profession that having a user use the product while giving us feedback is oh so much more valuable than performing a survey or focus group. The Journal of Consumer Research published by The University of Chicago Press has an article I must have.
"Is There a Substitute for Direct Experience? Comparing Consumers' Preferences after Direct and Indirect Product Experiences" by Rebecca W. Hamilton and Debora Viana Thompson.
We show that direct product experiences (e.g., product trials) and indirect product experiences (e.g., reading a product description) result in different levels of mental construal and product preferences. Study 1 demonstrates that increasing experiential contact with a product triggers more concrete mental construal and increases preferences for products that are easy to use relative to those that are more desirable but difficult to use. Studies 2 and 3 show that the effect of product experience can be attenuated by encouraging consumers to think concretely prior to product exposure and by asking consumers to choose products for others instead of themselves.
If you have a subscription, please let me know if the article is worth the subscription cost. I am looking for some metrics that show the benefit of product use versus recall or perception studies.