Used to use Keo black cleats. One of my cleats went out of adjustment and I couldn't get it back to the right place, so I decided to try red cleats for the time being. I think the extra float is actually a detriment, as I find I need to make sure my foot stays in the optimal position. If I stop paying attention, I'll find my foot turned too far in the wrong direction.
I'll probably move to gray cleats, or back to black after I've worn down the red cleats.