The two programs are really very different, although it's easy to get confused. Let's try to explain the difference now.
Nitrofocus is a program specifically designed to help enhance your concentration.
It consists of a dozen brainwave entrainment MP3s in total, each designed to help support improve your focus in different ways.
Of these sessions, five are the "main" focus audio sessions, lasting 60 minutes each. These sessions can be played on repeat, and are each designed to match your mood. For example, there is a focus MP3 for the gym, one for listening when you want to be more creative, one for listening later at night, and so on.
So, Nitrofocus = comprehensive brainwave program for increasing focus and productivity levels.
The Brain Salon is a series of six brainwave entrainment MP3 "shots" to help change your state.
Each MP3 is 30 minutes in length, and there are sessions for focus, relaxation, mood improvement, creativity, sleep and energy. Simply play the session to activate that state of mind.
So, Brain Salon = quick-fix MP3s for changing how you feel.
To answer the question: yes, there is slight overlap between the two programs, although there are really quite different. Nitrofocus is a substantial program specifically designed for focus and productivity, with a whole host of sessions to support that process. The Brain Salon is a "pick-and-mix" of MP3s providing access to common states, quickly -- one of which is focus.
If you're specifically looking for enhanced focus and greater productivity, then trying out Nitrofocus is a must. It's a powerful and comprehensive program built on the latest brainwave entrainment audio technology. If you're happy with just a little improved focus every now and then, the 'Razor Sharp' MP3 inside the Brain Salon should suffice.