To be totally precise : They are nor CP nor CA in terms of CAP theorem.
They only have "5 nines of availability" and they do not define exactly what they mean by availability here (transaction? Uptime of the server ?)
They are not Consistent in the CAP theorem proof meaning. They are serialiazable, not linearizable. That is not a big loss, but still.
To achieve that, they use a synchronised enough clock, using atomic clocks and GPS clocks. Which is quite the heavy machinery.
They "cheat" a bit on what they allow as operation. No DML operation, a lot of locking. And your response time will not be consistent for request that are the same and all. They claim "ACID"... but that term is loosely defined in term of distributed system and transaction meaning.
All in all : yes it is great. Use it if you want it. But no it is not a real solution to the CAP problem if it was a problem that mattered to you
Basically... nearly noone should need that, but everyone will use it because "aaaaaaaah we are loosing data !!!!". This is a great business decision from google pov, at oracle db level. But you probably do not need it.