JoomUnited website is historically based on Joomla. Almost since the beginning, we were using the same tools to manage our SEO. One extension to manage sitemaps, one extension to manage canonical URLs, one to manage redirects, one to manage structured data and so on. Discover how we've migrated to only one extension, 4SEO, to manage all that.
The former extension for Joomla we've been used for years has a classical approach to list page URLs in sitemap using Joomla menu and article list from the database. It was working great but requires a lot of work to maintain it because the system of URL inclusion and exclusion was too complex using direct SQL requests!
4SEO has a really different approach, everything is based on a crawler that runs in background. The exclusion of content mentioned can be done with regular expression (or just by adding a star suffix to URLs if you're not familiar with), so it's really powerful and yet elementary. The sitemap is generated and updated every time a crawl is finished.
As your website is growing, there is time when you need to switch components or just change the type of URL Joomla is returning. There's a great redirect component included in Joomla by default except that it only works on 404 errors, that's a pity. The 4SEO redirect manager is way more complete and handles all types of redirect with, again, rules based on regular expressions. Plus, it monitors 404 error generated by external websites, like website that make an extension review and point to an old URL.
Structured data for content, for us extensions for Joomla and WordPress, usually requires another component. Now we're using the 4SEO inbuilt tool that is very efficient and handles many type of structured data. What we liked the most was the possibility to define many conditions to load the data like by URL, Joomla component, category, dates...
Duplicate content and canonical may sound like something that is automatic with a proper configuration of your website. Yes and No, because some 3rd party components are not well coded and therefore generate many URLs for the same content. 4SEO is able to crawl properly the page address and detect this issue. You can also force a URL to be canonical from the crawl results.
The specificity of our website content resides in the multilingual system. It's based on Linguise automatic translation and generate many new contents. Basically, when a new page is added, 19 more pages are translated and need to be indexed fast using sitemap. And everything is working properly thanks to the integration of both extension / SaaS.
This is just our experience, but don't think twice if you have an important website (in size) or managing several clients. 4SEO will be a time and money saver for this usage.