You should definately send a rant to Delta in writing.
I would not say that this is typical Delta service, but the lingering effects of the winter storm combined with the mess that is air travel in NYC. Many flights were cancelled on every airline around that time, so there were a huge number of stranded passengers who needed to be accomadated in the following days (hence the three day wait for a confirmed seat).
Generally, I would avoid flying via New York unless it is your final destination, especially in the winter. JFK / LGA / EWR are barely functional on a good day, and are a total disaster when faced with any kind of irrops. The FAA or the Port Authority really needs to do something about the situation in NYC.