Reaper 7.0 default theme:
There are sooooooo many problems with this in my opinion. It's borderline abusive.
Studio One default look:
And with the meter bridge and small channels:
Everything is pretty clear. No weird alignment issues, buttons don't jump around randomly based on the size of the track headers. The mixer gives you professional features like ... erm... dB markers on the meters... because why would you ever not want that... There's loads of small workflow-y things that a screenshot cannot convey. Like selecting multiple tracks and inserting the same effect onto each one of them all in one quick motion.
Studio One has very very nice workflow.
Cubase Pro 13:
And the mixer:
And colourising the channels:
This is probably my favourite software mixer across any package out there. The meters are super clear and readable, very informative. Being able to hide away stuff you don't need at any given time, just makes the whole thing a joy to use.
Reaper just doesn't even compete with Studio One and Cubase, in my honest opinion. It has so many workflow niggles, look and feel mistakes, and on the whole as a software package, it just sort of .... I feel like it hates the user and wants me to die.