Suggestions for breaking up a large review?

Gewdo - Thank you for the kind comments. Glad my posts have helped.

I'll describe what I've done but I can't tell you whether it's best or not - only that it's worked well for me.

From the start, each review has been on its own post. I do not spread them over multiple posts. However, the content for each review is broken down into the same six sections and those sections are in the same order in each review. The section titles are wrapped in H2 tags and some include the product name as well as the section description for additional SEO benefit.

At the top of each review is a clickable table of contents with a hyperlink to each of the six sections so visitors can jump to the section that interests them most. There's also an "elevator" below each of those section titles - a hyperlink that says "back to the top" so visitors can get back to the table of contents quickly.

Using the same table of content layout for each review sort of "trained" visitors to know where to look for the same information on each product. I include a text affiliate link in each section so there's little chance they'll see a section that doesn't have an affiliate link.

Some of my reviews have grown to almost 4000 words now and on those longer reviews I've even found new sections to add. I just modify the TOC for that post to include the new section.

I considered doing multiple pages at one point, but my longest review gets a lot of traffic - repeat traffic, even. Some visitors leave me a question to answer. Some visitors leave information to help other visitors. Keeping it all on one page just seemed easier than sending visitors from on page to the next.

Here's the website that gave me the idea for using a table of contents inside the post itself (you can see an example, learn how to do it and read up on the potential SEO benefits): Optimizing for Rich "Jump To" Snippets - Yoast