My graduate E&M course was actually taught out of Schwinger, which I thought was quite nice. I would never recommend it as a first run through E&M. Jackson's p

My graduate E&M course was actually taught out of Schwinger, which I thought was quite nice. I would never recommend it as a first run through E&M. Jackson's problems are more technically difficult than, say, Purcell's, but how much of that difficulty actually helps with understanding E&M?