Raphael: Actually that's not quite true - 'cause in fact Ortofon still makes a couple of OM/OMP models for the international market, as one can see on their website. But there can be even more: For example, over here in Germany the SuperOM family has already been reintroduced in mid 2009 - and we also still officially get a couple more models of the OM/OMP range as well as the complete VinylMaster range (if you're curious what exactly is being officially offered over here, just visit the website of the German distributor: http://www.audiotra.de
Well, and as for the different sounds: You have to keep in mind that the generators are slightly different. Currently there are 3 1/2 different generator variants available: OM(B)/OMP (450 mH/750 Ohm), SuperOM & 5x0II/Vinylmaster (580 mH/1 kOhm) and finally 2M Red & Blue (700 mH, 1.3 kOhm) and 2M Bronze & Black (630 mH/1.2 kOhm). So it's no wonder that even the models with identical needle quality level (e.g. OM(B)20/OMP20, OM20Super, 520(II)/VM Red, 2M Blue) all sound bit different, provided one runs all with the same load parameters. Whereas the differences can be significantly reduced, if one adapts the load (foremost capacity) accordingly. And another thing one should not forget is the higher output level of the 2Ms, which requires careful level matching for comparison...
Greetings from Munich!
Manfred / lini