It depends on the host OS and codec. On Windows if your OEM didn't include the H.265 license with your default installation you have to buy it for $1 from the Windows store (this is a Windows thing, not a Davinci thing). On Linux I think you have to pay for the Pro version which includes the license.

I think if you're working with DNxHD files you don't have to worry about this.

I did some semi-serious work in Linux on the free version earlier this year. Performance was pretty good, and I believe that it did use the GPU.

The only big annoyance for me was the lack of a h265 codec. I had some FFMPEG shell scripts for the final exports, but it was a pain and I eventually paid for the full version, which I am very happy with considering it is a lifetime license. Some premium features like speech transcription, where you can select a video segment by simply selecting dialog from a text box, were a big time saver too.

With my last editing experience being Adobe Premiere in the early 2000s, Resolve was simply amazing.

Similarly, I use Shutter Encoder as an early stage of my pipeline to convert to less painful codecs.