> much less discoverable

That's not necessarily an issue if we're essentially talking about power users. If the app is worth its salt, then professionals that can make use of it will learn the ropes (so long as there is sufficient material -- help docs, tutorials, screencasts, etc). A good example is to look at text editors like Vim or Emacs. Much of their functionality isn't very 'discoverable,' but the power locked inside drives people to learn. Especially if you plan on diving into a particular profession. You want to use tools that make your job easier, even if there is a steep initial investment of time to learn the system.