[draft] Observable.Create allows you to design or plan to create an observable. It allows you to control and intervene the subscription phase of the lifecycle. You have (maybe too much) freedom about what you want to do once an observer subscribe your observable, but timing wise, that’s it. You have to do whatever you would like to at that time. When compared to subjects, you need more God-like abilities. You provide a scenario or a plan with Create in advance. With subjects, you can feed an observable in specific cases anytime. Creating streams with subjects seems more powerful, but it is more error-prone since you have to manage the state and lifecycle of the observable.
[a simple cold observable example here]
[trace sample that Lee Campell shared on stacoverflow]