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.
Ubersuggest is well suited for people who needs to conduct a basic keyword research to rank content in google. Whoever, the tool can be limited for people with more expertise and SEO knowledge. Nevertheless, having more free tools than other similar platforms, I recommend it to those who are starting in SEO.
It's really easy to use. The interface is nice and tidy, and the learning curve is low. So it's a tool that's accessible for everyone. If not, there are plenty of guides in the tool itself or on the website. You can easily make lists and export data for use or to share, connect Google Drive, and go work with a team.
They have a lot of information on their website, and also training and contact options in the tool. So you can learn on the go while trying the tool. And if you are stuck, support reacts really fast--sometimes the same day, sometimes the next day due to time zones. Payment is easy and easy to cancel.
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.
Very good and easy for those starting out. There are other more robust and better featured products, but they are more expensive. The others also have phone support options, which I have found very useful in the past. For larger companies I would probably look at someting else, but Ubersuggest is good for most SMBs