KeywordSpy is appropriate for most Internet Market research companies. I would not suggest it for a corporate marketing department unless it's a company with a very larger budget. This is also not a tool for small freelancers even though there is a free option, to get the best benefit of KeywordSpy it's best to use most of its features and options and this can get pricey.
SEOTesting.com is great in monitoring the results of implemented SEO optimisations. SEOTesting.com also has extensive content analysis reports that make it really easy to find long hanging fruits for content optimisation. However, I would not recommend SEOTesting.com for rank tracking and it has no tools for technical SEO. But if you pair SEOTesting.com with some other SEO tools of your preference, you get a really valuable toolset with decent pricing.
SEOTesting.com is NOT all-in-one SEO tool. But what it does, it does really well.
Rank Tracking requires to fill landing page per keyword. That doesn't make sense as the desired landing page is not always the best ranking landing page for each keyword.
Dashboards timelines should have some options to select only the desired timeframe. Then it would be sometimes easier to look at only the last two months for example.
Most SEO and market research tools offer what KeywordSpy has but are not as detailed and in one place. Consequently, where you can do everything at KeywordSpy, with other tools you find you have to purchase multiple tools or subscriptions from different providers which also don't integrate with each other. KeywordSpy makes your research easier and more efficient.
SEOTesting.com is a very specific, focused too. It's not "better than" the other tools. It does something they don't do well: gets data from your SEO results out into an easily-read, easily-reported format so you can 1. learn from what's working and what's not 2. show your team what success & failure look like 3. demonstrate to your boss/client the short-run benefits of investing in SEO Search Console has all the data in it. In fact, SEOTesting.com gets its data from Search Console. But you are going to waste your time and your colleagues time if you try to monitor granular, week-by-week progress for different pages in Search Console. SEOTesting is awesome at that. Use Ahrefs and/or Semrush to get ideas on how to improve your website's content and tech SEO. Then make the changes. Then use SEOTesting.com to find out if it worked!