I'm not a video person, I've made an occasional slideshow but even that has been over a decade ago. Recently, I needed to edit a video of an event and splice in the live recording with some pre-recorded segments and stitch it all together with some simple transitions. I didn't know what the "standard" FOSS offering was when it came to video editing. For photography I would go to Dark Table, GIMP for images, but what for video? I knew that Blender was an option but I wanted something with less steep of a learning curve even if that meant it was less featured. Luckily, there are several articles listing and comparing options, Shotcut and KDEnlive seemed to be the two worth investigating.
I started with Shotcut because it seemed like the lighther of the two packages. There were ample and good tutorials on YouTube that weren't too out of date, which got me up and running fairly quickly. Though I'm not a video person, I'm familiar with multi track editing and transforms, I just needed to know where the tools were and what they were called.
The interface was fairly intuitive after watching a short tutorial to get familiarized. It did slow down, choke, and crash a few times when working with my 3.5 hour long source video. The timeline zooming in and out (to make precise cuts) were a bit painful until I could cut everything into clips. I quickly learned their keyframe driven actions and also learned how to make a picture-in-picture transform. With all manipulations being filters, configuring transitions was also pretty easy.
However, the problem was stability. It crashed a few more times and then wouldn't preview the transitions at all unless I removed them and re-did them. Finally, it had lots of issues exporting (a big one was it having path issues that likely was more of a guix package manager complication).
I turned to KDEnlive after it was recommended by the System Crafters community [1]. The workflow was very familiar between the two programs. Both of them support rearranging panels to customize the UI, that also helped in coming up to speed. The filters/transforms work a bit differently but there are again plenty of YouTube tutorials. KDEnlive has a lot more functionality it seems but it doesn't force you to use any of it to accomplish your task. It was also noticeably more stable (no crashes even with a 2.25 hour video render) and snappy (the timeline editing and zooming was never laggy or froze up the UI).
All in all, I would say both are good but I personally had a better experience with KDEnlive, even though I much preferred the key framing UI of Shotcut. The stability issues of Shotcut could very well be specific to my machine and environment, so I'm not writing it off and might revisit it. KDEnlive produced a quality video where the editing seems passably professional, which is a testament to the tool and not my skill. It's amazing to have such high quality FOSS software, thank you devs!
[1] https://wiki.systemcrafters.cc/community/chat-with-us/