I have used fill in the blank forms but rarely get a response. If I can find an email, I will use it. I often times get the email of the current CEO and have mixed responses like helpful, antagonistic and none at all. Some of the responses are from the CEO themselves, and others are from lackeys.
FWIW:
I never use "fill-in-the-blanks" response forms. (Same goes for eBay surveys and the like.)
TOO easy for users/customers to complete, so I imagine companies - like Apple - get tons of these . . . which are easily ignored at the other end.
BEST BET: Take the time and effort to send a letter/email (if the issue matters enough you). The chances are better that the recipient will pay closer attention to it. No guarantee, of course, but it does show that the Sender was more earnest, IMHO.
