I would get the one you prefer as far as color, not steel. This is just my opinion based on experience with different "magical" steels. If you like the blue, jump on it, if you like digital go for that. My opinion is the whole steel thing is more hype than actual verifiable performance.
I can't tell the difference myself in one stainless steel to the next save for H1 which clearly has rust resistance. To me stainless steels are pretty much all inferior for knives EXECPT when it comes to corrosion resistance. As long as the overall quality of the knife is high (Spyderco Para definitely qualifies) then what stainless steel is used is pretty insignificant, IMO. So I would never pay $300 for a Para because it has one particular steel or another. In fact before paying that much I would buy two currently available paras in different color configurations.
Lastly, I really dig the blue but it would be a backup alternative to a black, OD, digital, etc. for me.