I always hear people saying carbide bits work fine and that diamonds are overkill. True carbide works just as well when sharp, but who the hell wants to change bits every four or five cuts? Especially if you run mod and cut the motor every run. I've had the same diamond bit for three years in the same lathe and not once have I had to touch it once I got it setup properly. I just got a Hudy lathe and put the same bit in it and it still cuts flawlessly. They're more expensive but well worth not having to deal with swapping and changing and realigning the carbide bits.