I have a site that at the moment uses the domain root (product-name.com) as the site starting point (as usual). Since the domain is a name of the brand and does not necessarily tell anything about the usage of the product I was thinking about redirecting product-name.com -> product-name.com/product-type/

Firstly, what do you think - is it better seowise to use product-name.com or product-name.com/product-type/ ?

Secondly, would the site rankings drop if I chose to redirect to product-name.com/product-type/ ?

Any fruitful ideas would be greatly appreciated.