I would definitely get the Storm. I don't like "pure" SS handles, so the grip inserts are very helpful, I like the recurve it uses, I love flippers, and I like framelocks better than lockbacks. Sandvik steel is no slouch either.
They're actually very different knives, if they appear to be for the same overall purpose (large inexpensive EDC).
The storm series feels almost like a secret among Kershaw fans...I keep thinking that if only everyone knew how much knife you got for how little cash, every person would have one (which clearly is not the case).
The Endura is a legend, and I'm a Spyderco guy in general, but I'm one of very few people that thinks the Delica/Endura line has better options, even within Spyderco's own lineup.