There are many times that this issue arises in forums and it is not easy to answer because each situation is different . The cache plugins are very useful but not necessary at all times, and in some situations they can even be counterproductive.
Let's see their advantages and disadvantages …
Advantages of the Cache Plugins
] Basically what they do is make copies of the content of your blog in static HTML pages that are what your blog will serve instead of the original content, so that is not done even a single PHP request to the server everything loads faster to not have to serve each visit all the content, and that's good.
On the other hand, the current plugins withor do not leave your blog dead but is refreshed every time you post a new post or someone writes a comment .
They are very useful if your blog receives a lot of traffic and the resources of your server are not unlimited and they are especially vital, in fact indispensable, if you receive a barrage of unexpected visits by a " wiggle " or similar. In those cases, only one cache system will keep your blog online .
Disadvantages of the Cache Plugins
Its virtue is also its disadvantage, since when serving static pages will not update properly active content of your blog such as rss feeds that show, rotating banners, social network updates or random images, all those virginities of modern WordPress themes.
Also, although most allow filtering agents (allow to pass through the cache to certain services such as bots), there are online revenue systems (Backlinks, Text Links Ads, Linklift, for example) that will not work properly if you have active cache and can unsubscribe from the service blog … and stop receiving revenue for that service.
What is my advice? since you always have a cache plugin installed and active, or not working, waiting for it to be needed . If your server is able to serve your blog in a reasonable time most of the time is not necessary to serve static pages, let your blog show in all its glory. And only if you see that you receive a trackback of social aggregators type menéame put it in march in anticipation of disasters .