I have a Swiss 1975 Montres Omax Crystal Automatic and just got a 2013 Indian HMT Kanchan Supreme.

The Omax Crystal supposedly has the AS2066 25jewel movement with day and date adjustment.

The HMT Kanchan Supreme has the Miyota 8215 21 Jewel movement with day and date adjustment.

Which is a more reliable and worthy movement?

I am asking because I am interested in acquiring another old Omax Automatic or getting another HMT automatic or Allwyn automatic for collection.

PS: What movement does Allwyn automatic has?