[Plugin: WP Super Cache]optimal settings for no comments / almost static site?

Hi,

I have wordpress blog with more than 4,000 posts, the most visited pages are the category pages.

The blog is almost static, there are no comments included anywhere on the blog, and global settings for blog is also disabled.So, it wont be that bad to consider it as almost static site.

This site pages change only when new post is published.

So, my question is what would be the optimal settings for wp-super-cache expiration?
a short one for e.g 300 seconds as mentioned in https://www.ads-software.com/support/topic/234995?replies=8

or the higher one would be better as it’s almost static.

Thanks in advance for your insights:)