Damian Johnson:
Actually, both Tails and the Tor Browser Bundle could benefit from a usability study.
Usability studies only help if there's development resources to make the suggestions happen.
Tor Browser has had a study or two. It has been helpful even though we have not yet had the ability to implement the results.
< Mike and Tails should be the ones to make the call about if they have the bandwidth to take advantage of a usability study or not.
There are more people that can help - a study could also include a patch to move things in the right direction. Especially if they have evidence that suggests that they deployed the patch and found it to move things in the right direction.
All the best, Jake