Will it make much of a difference if you use the same meta phrase on every page of your site? or is it more beneficial to type a description relevant to that particular page?
Always use different and relevant description meta tag for each web page, do not use the same description meta tag on every page. You can review my FAQ on meta description tags at the link below. It contains basically the same information I told you here, maybe with a few extra things. Check Out: How do I use the description meta tag?
I don't think meta tags still help as google added no more weight on this one,. But I still suggest you to use meta title as it still play an important in terms of SERP for me,. Use different titles in different pages,. make sure it describe its corresponding content
Whats with the new image? Where did TAZ go? The post in CivicSEO hits the nail on the head. Also see This Post on Meta Tags
it is good to have a different Meta phrase to different pages it is easily search and give information to relevant page to visitors.
Create different description on every page to make every page unique. Make sure that meta description is related to page content. Meta description helps your visitors to think that your page is relevant to his/her query.
As the contents change with pages there would be different keywords than previous that emphasis on this page contents so obviously you will have to change the Meta phrases for each page. Title : Relevant to THIS page. Keyword tag : In decreasing order in importance of keyword Description tag : It should summaries THIS page content.