Updating critical pages?

Redirect or rewriting on same URL? Best practices?

[followgreg]

Guys

I just wanted to know if there is any best practice in the following case scenario:

> One of our critical pages: main product description, linked from the homepage and internals as well, including one of our main KW in the anchor text

> PROBLEM: the description became obsolete, we need to totally rewrite the page and change the anchor text on the site. But basically this is simply the newest version of the product.

> QUESTION: Should we simply redirect the old page to the new one OR should we keep the same URL and overwrite the old content with the new one?

I was torn with this problem for hours, is there any expert with an answer to this one?

Thank you!