There was a survey on Wikimedia branding (including branding of its projects) in Wikimania 2016. I was reading the results and I found it fascinating that Wikidata logo is liked the most between community people.
Notes:
"The barcode is great"
"It is quite clever, It spells wiki in Morse code" (I didn't know that. I checked it and it's true. WOW)
"In terms of semantics, It's perfect. The color, font, barcode"
"It is simple and obvious"
Best