I don't have much issues with metal drip tips but I don't like aluminum drip tips. Which is weird because the taste I get from aluminum drip tips aren't apparent with the metal dt's I have.
To me, the best would be plastic drip tips because I absolutely don't get any sort of weird aftertaste with them. Plus, they don't get quite as hot when you use them with atomizers. Only use my metal dt's with cartos.