While I agree that there was no need to for "tone" from the controller, I think you should have said that you'd be doing 165kts instead.
DFC - can you say where this mythical +/- 5% for speed is written please? I think it's something that is a bit of an urban myth to be honest - especially these days when speed can be more accurately flown and indeed aircraft are being vectored much more closer together than years ago. Just how happy would you be having been vectored to min vortex wake against a heavy - to find that it's doing nearly 20kts slower?
Funny how no one thinks that there's +/- 5% on headings or levels!! FL160 = anywhere between FL152-168?
louby