What do you like best?
If you want a color grading program, get Resolve. There isn't anything better. The only exception would be if you need something that integrates into your NLE like a plugin. But if you are serious about color, you can't tough Resolve with anything else. I've tried, and have uses for Magic Bullet Looks and Colorista, as well as other tools like SpeedGrade, and FilmConvert. But at the end of the day, if I'm going to seriously grade a project, it happens in Resolve.
Additionally, this thing has the best tracker of any program I've used—including Mocha, Fusion, and After Effects. It rocks.
I love that Blackmagic is trying to make this a full featured NLE. It's not there yet, but it's getting better.
What do you dislike?
The NLE functions are fledgling. They hit checkboxes, sure, but they just haven't given it the time it needs to be a real, seasoned NLE that gives a great editing experience. It's nothing major missing—it's a hundred small things that add up to lost time. Tasks take one or two clicks longer than in Avid or Premiere, keyboard shortcuts don't exist for certain tasks, or behaviors don't happen the way they really should.
And none of that is a knock against Resolve or Blackmagic. I firmly believe they'll get there, in time. It's just not there yet.
Recommendations to others considering the product
Don't question it—if you want to do color grading, get Resolve. The only reason you may not want to is if your computer is very underpowered. But my 2011 MacBook Pro runs it well enough (with 4K footage in proxy mode) so you probably can make it work.
Don't be intimidated. There's a rumor that Resolve has an intense learning curve—it really doesn't. It runs just like any other color grading program I've used.
What business problems are you solving with the product? What benefits have you realized?
Like Fusion, this amazing, full-featured powerhouse of a program is FREE, or under $1k for the whole shebang. That's unbelievable. This program used to cost thousands, and is now free with more development and continued improvements.