I should modify my response. I was thinking of steel when I posted. EDMs are very good at cutting up hard to cut materials. Ti, Cobalt alloys and even carbides can be cut quite easily. (One of my customers does 95% of his work on cobalts and carbides using mainly EDMs. He also does machining of carbides using polycrystalline diamond (PCD) inserts) If you work with exotic alloys, and can get it cheaply, it might be worth it.