What I really like about them is extensive detail including the keyword difficulty. Ahrefs uses clickstream data to also show how many clicks you will get from the search engine. This is very useful after knowledge graph integration, as many keywords may have huge traffic but they hardly get any clicks from the search engine. Reason being, they get answers directly from the Google search result. Example of one such query is: “birthdate of any celebrity”
Let's say you're considering starting a new website, or venturing into a new product niche. And, suppose you'd like to somehow determine how much search buzz is currently hovering around this topic. You can use Keyword Researcher to get a "feel" for how much interest is actually out there. For example, let's say you were selling cameras. Then you might consider the following:

Positive reviews from hundreds of users have shown that Long Tail Pro by Spencer Haws is the supportive tool available for internet workers. It is a reliable tool, which would help you to stay on top of your competition by ranking topmost on the search engines. You can test run the program before you buy it. It is highly recommended for every internet marketer.
Google's AdWords Keyword Planner tool is another common starting point for SEO keyword research. It not only suggests keywords and provides estimated search volume, but also predicts the cost of running paid campaigns for these terms. To determine volume for a particular keyword, be sure to set the Match Type to [Exact] and look under Local Monthly Searches. Remember that these represent total searches. Depending on your ranking and click-through rate, the actual number of visitors you achieve for these keywords will usually be much lower.
If you are somewhat new to this whole ‘make money online’ thing – then surely the cost of Long Tail Pro is a major factor for why you haven’t purchased it yet. Believe me – I know! When I first started out – I refused to pay for anything at all. I did everything the free way. I tried doing all of my keyword research with the free tool that Google provides – and my keyword research efforts were terrible! You know how I know? Because my sites weren’t getting any traffic and I wasn’t making any money.
"This is the only keyword research tool that I recommend. The ideas, inspiration, and content longtails you will get for your niche topic are going to result in you producing a page of content that is more than going to pay for this tool. And as they are Google's database then we KNOW that these terms are being searched by a decent volume of peeps every month. It's a goldmine dudes."
Keyword Researcher is designed to search the Autocomplete databases of Google, YouTube, and even Amazon.com. That's a lot of keyword sources! As you probably know, if you're building an authority site, or if you would like to become a dominant player in your niche, then starting with a large database of keywords (that your customers are actually typing in) is a powerful marketing tool.

I think people's aresenal of keyword research tools are mostly the same: 1) You need a tool to examine search volume, most likely Google Keyword Planner 2) A tool to help you generate more keyword ideas. Tools that work with the search engines' autosuggestions are very popular such as KeywordTool.io and Ubersuggest 3) Then people might add a tool broaden the depth of their data, maybe including something like Google Trends or Moz's Keyword Difficulty tool.
Keyword Researcher is an easy-to-use Keyword Discover Tool. Once activated, it emulates a human using Google Autocomplete, and repeatedly types thousands of queries into Google. Each time a partial phrase is entered, Google tries to predict what it thinks the whole phrase might be. We simply save this prediction. And, as it turns out, when you do this for every letter of the alphabet (A-Z), then you’re left with hundreds of great Long Tail keyword phrases.
The limit on manual keywords could be higher.  I personally wish we could input 10,000 keywords at a time, instead of 200.  However, I understand the costs that Long Tail Pro has to maintain each time a new manual keyword is input.  Not a deal breaker, I just wish the limit was higher. (To be fair, I don't think most keyword tools have a bulk manual option at all).