I was in the same situation that you are almost one year ago, and we decided to go with new blog posts for each tutorial.

One of the main reason was to target longtail keywords and we are doing quite good with that. And on some keywords we are getting the product page and alsot a blog post or two in the search result page so that is a plus because we have more chance of being clicked since we have more content.

Another reason was for social media and newsletter, we send out weekly newsletter so having new content on a regular basis was important for that also.

Hope this helps