Here is a quick rundown.
Things I know or are my opinions as a designer:
- Deja Vu Sans is a very vide font, and in many cases causes "ugly" ui because
of the amount of space it consumes. Screen space is at a premium and this font makes the
issue worse by being one of the widest out there. This is a big pain point in places like
dialogs and skinny window titles.
- Deja Vu Sans is known to be tricky to render on screen - some letters just have awkward
spacing and widths no matter what you do (bowls on d's seem compressed, etc). I
blogged about this as it relates to Fedora:
http://blogs.fedoraproject.org/wp/jperry/2009/10/30/when-rendering-text-o...
- it looks old - compare it to any other modern UI.
- The bold is really quite bad and amplifies the issues above.
Things I dont know as fact but suspect about Deja Vu Sans
- Wasn't designed for UI use specifically. UI fonts are not made for documents, or
vice versa.
- Hasn't been as rigorously crafted and tweaked by fontographers for best fitting and
spacing
OK. I did some quick comparisons which can be seen at: