When Tenaya conceived the new Mastia, they wanted to create an aggressively curved shoe that delivered maximum power for standing on tiny holds, but also one which provided unrivalled responsiveness in all situations.
At the start of its life, the Mastia has a good amount of stiffness and a sharp edge, but once they're worn in, they come into their own on more soft and sensitive rock types.
If you watched the video you'd see what I meant, but as a sweeping summary I was referring to rock types which require sensitivity over stiffness - not those who's feelings are easily hurt.
Clearly exceptions occur, but by and large gritstone, sandstone and granite benefit from something you can feel the rock through, as they're more friction based rock types. More edge based rock types such as rhyolite don't (necessarily) require the same level of sensitivity, as they benefit more from a stiffer shoe which will allow you to push off the most marginal footholds, which are - by their very nature - more positive (i.e. edge, not smear).