Use the clearest and simplest language you can. Your potential customers will have a wide range of reading abilities. Some will speak and read English as a second language. Some will be young. Some will have memory problems causing them to forget the first half of a long sentence before they get to the end. Some will have cognitive issues causing them to have difficulties concentrating on complex or long blocks of text. Simply put - the less demanding the text the more people can access your site and buy your products.

Read about how Read Index criterion scoring works.