Thanks. It's pretty much where I'm headed. Though I do not have ArcGIS server for most of my customers, and the features to display are not there for users who do, I've started to implement my own REST FeatureService to return the data. This seems ideal as then I do not have to maintain ViewModel to feature data integrity, and can just transform the data directly to information the featurelayer can handle (and hope updates to existing features is handeled, not just removing everything, and forgetting the previous state/selection).
My concern is updating the features, and selection. I was thinking of using TimeExtent, and hope I can use it to update the features every second, or whatever is required. I will not have historic data, and it will be real-time (within the configured time delay). And if I can update the features every second, will selection in the map be maintained when an existing object gets a different position or symbol?