I wish to point out I never change speed on my pillar drills. I do not have blowouts nor allow extra length to speak of with my blank preparation, the speed is medium, always works for me.
I was in Tasmania once when at a mill a large length of Tasmanian Blackwood fell off a fork lift, it rang like steel. The point is I have seen and used so much timber within species that proved to me there is no real normal.
I get hundreds of clean great blanks using DeWalt Extreme 2 drills. The toughest I find to drill is Snakewood and Ebony, one of my favourite timbers Hairy Oak can be really hard as well as some Red and Brown Mallee. Density varies tremendously, some of my stash burl is really tough and aged now. Like driving a sensitive touch is better than a panic hold.
Peter.