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:
A service like BrightEdge comes with the biggest costs associated, but its SaaS solution for SEO covers many areas inside of a single ecosystem, including the ability to explore keyword data. This may be a benefit for agencies that wish to reduce redundancies across vendors, but eventually, it is likely that the need for a second tool will present itself as talent and effort levels increase inside of your SEO department.
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).
To drive search engine traffic, whether through organic search or paid search advertisements, you need the right keywords, plus a process to expand your keyword lists over time. That’s where our free tool comes in. WordStream’s Free Keyword Tool gives you hundreds of relevant keyword results, plus additional, actionable information like competition level and estimated CPC, all for free!
While this one isn’t necessarily a keyword research tool, it will give you valuable insight into how the keywords you’ve been optimizing for so far are actually performing for you. You might realize that you could start ranking for more keywords with more difficult competition, for example, or that only keywords on certain subjects are working for you.
The link back to googles API is crap – it keeps coming up with password authentication which renders it virtually useless when trying to find your own rank. Sells you the software initially. But then tries to sell you a load of stuff afterwards which effectively tells you the first version you have already paid for is useless without the extra “bonuses”. Not a nice way of doing business
Google prefers to not share long tail searches in this tool – because the tool is designed for Google Adwords advertisers. If advertisers bid on those long tails – they would have less competition and therefore pay less for the Adword, and therefore Google would make less money e.g. bidding on the term weight loss for girls under 18 is cheaper than weight loss. 
For the first few months, there was certainly a transition period.  However, the new team was able to take over the reigns fairly quickly.  A big reason for the quick transition is because I had automated most of the business already.  So, the fact that I was stepping away didn't make a huge difference since all the sales, marketing emails, and many other details were already happening on an automated basis.