The Russian Sim Card did not work at all. I had to buy a Russian SIM CARD from MTC.
The European Simcard did work for Data but very unsatisfactory for Phone Calls.
Not really helpful in many regards. You better off buying a local Sim Card for crystal clear conversation.
Improvements or suggestions
There is a lot to improve which are too many to list especially in the Phoning category.
Data is OK for the average use for GPOS on Mobile Phones etc.