This is an engineered system by Oracle. It provides very fast communication between the storage and database. A lot of data processing is done at the storage level.
This makes the queries and processing much faster than before; reports can run within minutes rather than hours.
Cost is very high. It needs to be made affordable to grab more customer base. A lot of the technical enhancements are being made by Oracle regularly. Now, it is available on the cloud also.
If you deploy a normal server setup with SAN or direct disks, the cost is very low. Exadata machine is supplied by Oracle and hardware also maintained by Oracle. They charge as per their standards and pricing. Its quite costly in that regard.
I have used this solution for five years, since about the time it was launched.
There were no stability issues.
There were no scalability issues. In fact, scalability is one of its prime features, it is very flexible.
The technical support is, as usual, good from Oracle.
Earlier, we used SAN and the traditional servers. That was also good and time-tested for decades. This is all together a new concept.
It was a normal Oracle database setup.
The price and license costs are high as compared to the normal database setup. It depends on the client's requirements and size of the databases. Clients/ buyers have to take the call.
No other options were available in this category at that time or even now.
You should evaluate your requirements and budget.