this makes me think you've never used 60mm 2.8. If you had, maybe it was a broken copy, but in my daily practice it's lightning fast. I understand that if you're doing exclusively macro, focusing might take longer, but for regular portraits at normal distances this lense is THE fastest I've ever used.
It's in my bag, trust me I use it PLENTY. Used on a D200 and on a D90, I find the 60mm 2.8 to be slower than my 24-70 and 70-200. Maybe it's my body or my experience, but the 35 1.8 tops my current list of primes in AF speed when compared to the 50 and 60. . . but hey, that's just my experience on 2 bodies. Like Niko said, the metering and AF differs on all bodies and that could impact AF speed.
Curious, what bodies are you using to claim the 60 mm 2.8 micro your fastest focusing lens?