Cloudflare can significantly improve the performance of your website if you choose to use it. It can also help improve your SEO efforts. It may, on the other hand, negatively impact your SEO if it is used improperly. You may experience issues with link checkers, time delays on fast servers or Cloudflare reporting your site as down, just to name a few. You may want to give Cloudflare a try if the benefits outweigh the negatives.