Normally people think that you get better respect if you say your a MM and use the stationery, but I feel the opposite.

If you have that many miles, the airline might assume that your are tied down to them because of past loyalty. After all, why would you want to throw away all the miles. So if you show that you've flown them a lot recently (by stating your elite status) but do not say you are tied down to them by million miler and stuff, you might get a better response because they feel you might actually leave.

Now, in many cases, people, such as MisterNice, do leave. And this argument has lost a lot of validity since miles are now non-expiring for the most part. But it seems that many people here are tied down to airlines such as United that constantly screw them just because of the miles.
BizJet