I didn't tried their tools/services. But I know it is similar to Ahref.
They have 6 service packages including the Free. First try using the Free one... If you're satisfied with the actions then go for recommended paid one.
Customer satisfaction and feedback
There have pretty much decent clients testimonials by providing good quality of service. But every coin has two sides. Remember nothing in the world is perfect
May be 80-100%
Time it takes to start producing results
What type of results you need? Majestic SEO is a site analyzer & backlinks checker
Search Explorer (beta)
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