I do not know if this is V10 feature of just shows up in the Wolfram cloud. But when making a slider and moving it, the current value of the slider is displayed below where the current position is. This is nice, but the value is displayed in the wrong side! It is displayed below, which is where the mouse tip will be as one is moving the slider. Hence the current value will be hidden or hard to see most of the time, which removes all the advantages of showing the current value as it can't be seen. Here is an example. I'd like to suggest to put the slider value above instead of below the slider to make it easier to see.

   Manipulate[Plot[Sin[a x], {x, -Pi, Pi}], {{a, 0, "a"}, 0, 1, .1}]