Matt,
I had the same dilemma and bought the resin also. Did you get the Hi-Tech filters? I bought a few of the graduated ND filters. I have a hard time with fuzz and dust on them. I bought the filter cleaning kit linked below, and it works well. The spray is anti-static and helps keep dust from accumulating while shooting.
http://www.bhphotovideo.com/c/product/292629-REG/LEE_Filters_FCLKIT_Filter_Cleaning_Kit.html#accessories
Whether, to buy resin or glass largely depends on your budget. Definitely buy glass if you have the cash. I have heard that the Singh-Ray’s are the best. If you stick with resin, stay away from the Cokin’s. They are usually labeled as graduated grey filters and not graduated neutral density, “neutral” being the key word. The Cokin’s will cause a noticeable color cast.
Jeff