The 56mm is my most used lens. I like the perspective of the focal length for human subjects (I shoot fashion and portraits). The focus is faster than the 60mm. Although in good light, it doesn't make that much of a difference.
The 60mm is a great lens. The slow part of the focus is when the lens decides to go through the entire range to acquire focus. That takes like 1-2 seconds it seems and is unacceptable if I need to capture a moment.
But the 60mm has its uses since it has a much closer focusing distance. I take it out if I need to shoot something close and still. So for beauty work and product, it works great.
I suggest the 60mm if you're shooting at a slower pace and need to shoot things close up. It's also much cheaper. Because of that, it is a very versatile lens. You can shoot a lot of different things with it from product, landscape, and portraiture. I wouldn't shoot anything that moves with it though.