Hi. I have the predecessor to the 191, the RSM190. I have used it in multitudinous situations From the noise of Def Leppard in concert to the subtle sound of a lute solo. I last used it a couple of weeks ago to record this. I think that the main difference between the 190 and 191 is that the body of the 190 is metal and the 121 it's plastic. There may be others I don't know. It has been out in all weathers survived numerous airport security cheeks. I had to ditch the flight case it came with as it had printed in big letters on the side "Shotgun Microphone" They took great exception to this and gave me the third degree when trying to get through security. The archbishop of York's dog peed on it once, it was in a Rycote thank goodness and a $50.000.000 racehorse decided to try it out as an aperitif. I won't bore you any further with this tale and suffice to say, I just love this bit of kit. Thanks Neumann.