I have been using my Genmitsu cnc for several months and "experimenting" with bits. I have bought some "cheap" ones from Amazon to try to learn with and now ready to get some good bits. I have been using a 1/4"  carbide round nose bit to do my rough work. It seems to be doing ok but would like to do better. Is a carbide bit actually worthwhile for roughing or would "throw away" high speed steel do an adequate job?