I'm a fan of RxDB. It makes a lot of sense to combine something like PouchDB with RxJS to create a reactive datastore. The only thing that bothers me a bit about it is the dependency on CouchDB (at least in case you want to have online sync). Not that I have anything against CouchDB (it's a great piece of technology IMO), but it's definitely not suited for all use cases and is in general a lot more restrictive/less powerful than a more general-purpose database like PostgreSQL.