This is not so much a technical question but more a typographic one: Do you always use \left( and \right) instead of just ()? Or are there exceptions when smaller brackets are preferable?
For example using the autosized brackets in the following example looks pretty strange or is it just me?
You are right. It is not always desirable to have automatically scaled delimiters. Another extreme example is a sum sign with only limits above or below. But there are several (TeX) commands for manual adjustment. See the code below for comparison.