This is impossible to answer as it will be different for everyone in terms of what they value.
All you are getting is 4" of extra legroom and about 2" of extra recline. If you are 7 feet tall, it is probably definitely worth it. If you are 5 feet tall, you may not even notice the difference.
The service is the same (at least on international cabins - domestic C+ get free alcohol and extra snacks which is not the case in regular Y).
On the face it seems like a $200 one way upfare is quite pricey for a 12% increase in pitch - so unless you really value the legroom it may not make sense.