It'll work fine with the stock ram. The Eigenvalve and Eigenram give it killer efficiency though. The purge hole in the valve/poppet gets rid of possible pneumatic lock that the stock poppets can sometimes get (you'll never have to purge the valve again like it says in the manual). But, it also changes the pressure bias on the valve when it's open making it want to close quicker and save air. The Eigenram is lighter than stock, so it allows the valve to close even quicker still, saving even more air.
With that said, any combination of valve and ram will work fine.