I know certain colleagues of mine just hate tootling along at M.78, they always tweak her up to M.80 or M.82, which is perfectly fine (except for the higher fuel burn...naughty naughty!).
My first thoughts on hearing about the sonic whatssit was of those guys...they won't be happy doing M.98 or whatever...they'll have to faff around with it to get M.99, ...and then ooppps!....we've gone supersonic...BOOOOM!!!