Here is what I use when I open up an exhaust manifold; and when I smooth and blend the bowls and transitions in a cylinder head.

The short burr at the top is a double cut burr, standard length. The others are 6in long shanks, single cut. The long shanks make it easier to watch what is going on.

I like the angle tool; it allows better control. And with leather gloves on, I can guide the tips by allowing the shaft of the burr to rotate between two finger tips....the leather protected finger tips act as a pivot point. And I can feel the pressure of the grind better that way. Using carbide burrs on aluminum requires a light and sensitive touch. On iron, it is more fun: you get to really go at it...in comparison.