I had my own jury-rigged ghetto version of Rx (made before the official release, based on the initial videos etc. that were the only thing available at the time) that I used at my previous job where we had a distributed document-processing system with streams of document metadata coming in from extractors on multiple machines. The approach worked well but my implementation was pretty hackish, I haven't gotten a chance to use the official .NET version yet because there hasn't been much event-stream-y stuff at my current job. I did use RxJS a bit for some Ajax call chaining, and honestly it was probably a mistake as it was overkill for what I was doing (to be fair my struggles with it were probably mostly due to my inexperience with Javascript in general).