For these reasons, I still find ruby-debug better for actual debugging (when step/next are necessary) and pry better for inspecting state at a particular moment in time (but I can just call pry from the ruby-debug in that case)
Remember, pry and pry-nav are new projects, and bugs can usually be fixed. And the sooner you file an issue, the sooner the bug can be fixed :)
Also, being able to cd into and out of objects is fantastic.
taking a look.