I tried a RPi2 and it ran okay for one R606 but as soon as I added another it had problems.  A lot of errors and it eventually crashed.  I think the problem is the USB - it is just not great the the RPi1 and 2.
I switched to a RPi-Z (got it for $5 from Micro Center) and it has been running well for over a year with five R606's.  
It does occasionally go belly up for some reason but a simple reboot gets it going again.