We have worked for three days to install bare-metal Oracle Database Appliance (ODA) X4-2.
It amazed me to see how easy it is with Oracle ODA to create three Oracle RAC databases of different versions on this box in a single working day! For small and medium business databases, this box is worth the money. It is easy to manage, very efficient, and, of course, highly available.
On the other hand, with this box, you cannot add an extra node to your RAC database.