depends on the NoSQL approach you are heading for. Each NoSQL flavour has its distinct value.
However, if you need a document storage (like MongoDB) I'd prefer the elasticSearch solution:
- Monitoring: intertwined with the EngineCockpit, Logs, JMX... ElasticSearch is easy to handle in combination with Axon.ivy
- API: simple repository centred API with nice update mechanisms (actually inspired by Mongo DB concepts)