I just picked up this used Sadowsky NYC and am taking it be set up tomorrow. The strings need replacing and the action is a bit high for me. Question for anyone that has used the Sadowsky strings - is there a big difference between the black and blue series? I've read what's on the Sadowsky site (http://sadowsky.com/strings/difference.html) but was looking for real world experience. I'm currently using Fodera nickel ultralight (40 55 75 95) and figured I'd stay with a nickel string. Just wondering. Thanks for your input!