Hi pfav,
The other thread on which you posted the exact same question probably gives as much information as is available.
FWIW, my machine uses the 7206AC lower, 6206RZ upper as standard, but MarcuSweden is, I think, using the 30206Q for the upper and either the 32206BJ or 32206 QCL7 for the lower, however apparently the 32206 is slightly wider so the shaft is slightly lower so the top bearing only has about 70% contact.
Apparently as well, the 32206 handles more power than the 30206, but the 30206 is a considerable improvement on the originals.
The above info is extracted from the other thread.
Regards,
Peter G. Shaw