The rendering speed comparison seems to be just encoder speed and not closely related to the software itself because on Windows you can pick any DirectShow based encoder in any video editor.
For me, the most important aspect is how streamlined and intuitive is the software for most common tasks and for occasional use.
For example, friends bring you a bunch of video clips and images, filmed on different devices - cellphones, cameras, etc., with different audio and video quality, different video brightness, different file formats, and you have just a few hours to assemble it all into one coherent video for someone's birthday party. Assume, that you haven't used your video editor for a few months and have forgotten all specific keyboard shortcuts.
Now, how easy it will be to bring all those videos and images together, normalize audio volume, video brightness, create a slide show clip from image sequence, clean away audio and video noise, add simple transitions and some texts?
Is there any "magic one click button" which provides you with defaults for the task and then helps you to tweak the settings for entire track or individual clips?
Does the software support basic expected keyboard shortcuts for copy/paste, undo, scrolling, zoom in - ctrl-c, ctrl-z, mousewheel, ctrl-mousewheel? This might sound crazy but there are many programs where you still have to click on tiny up/down arrows to scroll instead of just focusing your mouse somewhere on the area of interest and scrolling the mousewheel. Some software even go as far as replacing default Windows shortcuts with their own commands, causing complete mess.
Does the software interrupt you with nag screens of their "better products" and there is no way to turn them off?
Does the software have some confusing UI controls which have the same name but work / do not work based on circumstances? Real life example - Render loop region checkbox in Movie Studio Platinum; it is displayed in two places and if you pick advanced mode, the first checkbox stops working and you have to use the other one, which is hidden under some barely noticeable dropdown.
Does the software turn out to be just an empty shell and you have to buy even some basic effects and plugins separately? Whats the point buying a program for 30$ if you have to spend 100$ to collect all the needed plugins for basic color correction, noise filtering, AVCHD import etc.?
So, please, next time you review these programs, please focus more on usability and bundled features for everyday use.