I went to presanctified liturgy at the Greek Church in my town, and noticed some differentes from the Russian tradition OCA Church I attend. one was that they don't prostrate nearly as much as we do at this service. they also had a piano just outside the iconostasis, the priest used a microphone attached to his vestments, and there were no oil lamps flickering before the icons, but electric light bulbs made to look like real lampadas.
is this commen in all Greek Orthodox Churches?
For the most part, these differences have more to do with the age of the parish than the jurisdiction or liturgical heritage. I've been to OCA, Romanian, Serbian, and Antiochian parishes with fake lampadas. Such things were very popular until the 70s. Same for organs and keyboards.
Lavalier microphones, however, can be found across the Orthodox world. I've seen them in parishes, cathedrals and monasteries in Romania, Russia, Greece, Bulgaria, Ukraine, etc. Many monasteries even have loudspeakers on the outside of the church, so the crowds that can't fit into the nave can hear what's going on inside as they gather around the building.