Being as WordPress has a nice looking CP but a real “mess-o-fields” when you want to do anything beyond a blog post with a gallery I wouldn’t think it was a remotely fair comparison. The problem lies with convincing a client of that when these days “quick and easy” seems to equate with “best option”.
The point with EE is you can change the admin interface quite a bit with various add-ons as well as the publish page (most important imho) being specific for your custom fields/layout.
The fact you can customise the publish page so heavily means my clients say the exact opposite - e.g. “I wish I could do that in WordPress”. It might mean you have to work harder in EE to get a nice result with the CP but I always think “Tough for me” = “Easy for my client”.
So I think YES! it should be a reason to recommend EE - it has a more flexible admin/cp compared to WordPress, there comes a point when jumping through hoops with WordPress becomes more grief than its worth and EE is ultimately more flexible and extensible with regards to its admin.
Not to say WordPress doesn’t have a nice UI - this isn’t a WordPress bashing post, but having been on the sharp-end with clients using both systems I know the limits of any UI testing will be based on how the EE admin is setup.
As EE is more like a framework so the admin area is flexible enough for to you to configure and deploy as best suits your client. Just about every EE site I’ve built has a different admin area or some tweaks to it to match the clients specific needs - so a comparison of EE and WP admin areas isn’t reasonable in terms of usability. One example is WordPress has a fixed WYSIWYG and EE doesn’t choose one for you - which is an immediate and very big difference in their respective ‘vanilla’ versions. Some clients find WordPress easy to use simply because of this WYSIWYG feature and everything else is compared to that experience.
So no, I doubt there are any usability comparison tests - but I don’t think it’s much use anyway as it’s comparing Apples and Oranges.
Interesting though that clients think “everyone already knows how to use it” - it would be good to know if they mean ‘the whole thing’ or just editing/creating content within the WYSIWYG.
Thanks for sharing 😊