I believe it is also linked to politics. Both the Russian S-300 and S-400 have never been tested in combat. The Hellenic forces have had the S-300 since 90's as well. The S-400 on paper has a pretty powerful radar and should have been able to pick any intruding flight with the The 91N6E panoramic radar which claims to have anti-stealth targeting range of 150 km (93 mi)
[ Maximum targeting ranges (detection ranges are wider) perhaps upto 200 kms plus. So all of Lebanon and Cyprus can be covered. The Syrians also have S-300 under Russian control, but that too is kept under wraps for political reasons as Russian Jews have a lot of influence.
Anyway, Russia is arming both India and China with similar arms, including the SU-30. So time will tell if they work against modern aircraft like Rafale, which the Indians have also bought and so far never used in combat.
