Everywhere you go there are warnings about how slow Slerp is when compared with Lerp. Indeed, the published algorithms support this. Slerp has many trigonometric functions while Lerp survives on multiply and divide. When I ran a test on my Mac, Slerp was less than 15% slower. How can this be? It may be that Unity is using an augmented Lerp when it is applicable. It could also be that an Intel Core i7 has faster maths for trigs than anticipated.