I am not talking vocal mics I am talking the Sennheiser 421 they went from a Alnico magnet to a Nedinium magnet * much cheaper * and differently effects sound quality. So to trick there customers into thinking it was still the same old 421 they used a weight in there microphone.
A bit of mis-information I think.....
The MD 421 II came about due to the very high manufacturing costs of the original MD 421, due to the large amount of man-hours involved.
So Sennheiser looked at several of the classic mics to see if there was a way of manufacturing them in a way that used less human labour (ie: more automatically).
The 421 II came about due to this process and the idea was to get it sounding the same but cost less to manufacture - the weight and clip stayed the same because the original was like that - nothing at all to do with trickery!
Customers wanted it like this - when Sennheiser built a replacement for the 421 (the MD 422) no-one bought it and the replacement was discontinued and the original stayed on.
In fact I rather like the original 421 clip as you can put the mic. at any angle without the fear of it falling down as it is locked.
They also looked at the 441, but found that any change at all affected the sound, so the 441 is still built in the original way.
The more expensive manufacturing costs mean that the 441 is almost twice the price of the 421 - if the 421 was still made the same way as it was originally it would be a similar price - that's about £300 / $600 more!
Shure have done the same thing - people continued to buy the original SM58 and ignored, for the most part, the replacements. The current SM58 is not like the original and is now made in Mexico rather than the USA (at least that is my understanding of the situation). I think that Shure have now stopped including hum-bucking coils in the mics (Sennheiser still include hum-bucking coils) which, in effect, halves the copper costs of manufacture.