You can also adjust the areas that are read for top, left and right as well, for example, I reduced the top guard change input to 50, I think and increased left and right significantly, then went a step further and rotated the entire widget clockwise a few degrees, because I found that I was never actually moving my stick toward "true north" in relation to the axis of the controller. This helped so much, that when I play on my friend's console I can no longer block or even combo as effectively.
Awesome tips everyone! Digging into the controller settings can definitely help a ton in terms of increasing responsiveness and being able to reliably combo. This week we'll be looking to release the training arena and the apprentice trials, so even if you can't find a friend, you should be able to practice your blocking via the trials or by setting up a practice session in the training arena.