TR3,
NO NEED TO SHOUT.
We'll happily accomodate whichever speed best suits but, as HD mentioned, if you offer the option of either 160 or 170 there is usually no consistency in the answer.
It's probably fair to say that 160kts suits the majority most of the time, but I reiterate, it is not a problem to accomodate something different provided the request is made early enough.
B.