My favorite part about the nanosuit 2 is being able to cloak, sprint, and nanovision at the same time, being able to super jump without changing to a strength mode, etc. The standard sprint speed in Crysis 1 was pathetic, and maximum speed lasted all of 2 seconds before running out. Yes, it was far faster, but I found it only to be useful in very specific situations, or just for fun (love dashing straight into a guy and knocking him down).
They're both cool suits, for sure, but don't forget how the new suit lets you stack modes.