NoSQL, CouchDB vs. CouchBase, What should i do? [closed]

Question

I started to encounter some issues on my production site, when having a web page that needs to load a very big ResultSet (currently coming from relational database, MySQL) it takes forever, and problem these result sets are only getting bigger and bigger.

I started to seek after a better solution, and what I came across with is the idea of saving the data in a NoSQL database. (I'm already using Mongo, but Mongo is inefficient due to high amount of DML in my environment.) So when searching the web I thought about the following 2 options:

1. CouchDB
2. CouchBase

When looking at both of the above, I can tell say that both are JSON document based (ok, that's a good start), but when getting into some technical background I do look for better caching (I don't wan't to kill my server's I/O) then MongoDB's master-master replication ability (I saw that CouchDB can replicate easily based on source->destination / destination->source).

Can someone provide me some of your input, and if you had tried the above solutions I will be happy to hear about your experience.