The sideways quick stop is in my opinion sometimes a more comfortable way of slowing the ship in certain circumstances. The times I have done them usually came about due to my need to see what and where was in the direction of travel and the natural tendency to protect my tail rotor.
Nearly always it was instinctual, I definately felt more compfortable doing it. I have to admit it was usualy when working the machine reasonably hard in the mustering environment.
As an add on, I have also flared during auto's in the same manner, and as John E mentioned, it is a top way to terminate into wind which was usually the reason for doing it. I find I can judge my landing area at the end of an auto better using a turning flare. I think maybe this is because I have a natural tendency to overshoot the landing area slightly (more options than undershooting). Using a 'turning' type flare I can do more corrections at the last moment, and see the area more clearly, to nail the landing point. Of course the ability to level out at the appropriate time is important to say the least. RRPM is also a winner from a turning type of flare.
This is a personal preference thing and I have to admit that I have lost count of the number of times I have done auto's to the ground so I would not try to tell others to go and try it out on a whim.
Cheers.