When comparing KDENlive vs EDIUS X, the Slant community recommends KDENlive for most people. In the question“What are the best non-linear editors (NLEs)?” KDENlive is ranked 1st while EDIUS X is ranked 11th. The most important reason people chose KDENlive is:
Kdenlive is licensed under GPLv2, and built on top of other open source projects like FFmpeg.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Open Source
Kdenlive is licensed under GPLv2, and built on top of other open source projects like FFmpeg.
Pro Works great as an audio editor
Audio is edited in the same way as video, which makes it one of the best audio editors.
Pro Surpisingly complete
Although this editor is not up with the top of the professional pack of editors, it certainly packs a powerful punch, and should provide enough features for amateur montages, ranging from alpha manipulation, to multiple audio and video live track editing.
Pro Its great for learn the basics of video-editing
Pro Subtitles included
Pro Very good codec support
Supports MXF, MOV, MPG, AVI, MP4 etc and all kind of codecs.
Pro Fast working with good predefined shortcuts
very fast editing with mouse and shortcut.
Pro Very stable
Much better than PremPro. More stable than Resolve.
Pro Very fast
Cons
Con It's laggy and freezes, with some chance of crashing
Con Timeline cursor is not working
Timeline cursor is not working well on Kubuntu, very difficult to use it. You have to switch all the time between project monitor and clip monitor to get it work.
Con Dose not work well in Windows
They do not support windows well like other distribution. You will face a lot of problems.
Con No hardware acceleration
If you don't have a CPU that's good for video encoding, the render time can be quite bad.
Con Does not have good distribution channel
You have to go to their website to get newest version, does not auto update via package manager.
Con Doesn't support multi frame-rate video editing
When you choose the mixed frame rate option, your video with 60 fps will be broken (slow down and trimmed).
(This con might be just misunderstanding of how to do video editing and production from the user who typed in).
Con Complex special effects
Is better done in Fusion or After Effects. EDIUS install good codec for video exchange.
Con Some audio effects missing
E.g. track based effects or special filter.
