As they said, EU servers seem to have less available bandwidth, thus lagging more frequently.
US servers have more bandwidth and since latency time is not really important in this context they might perform better.
If you don't have any problem don't change anything
Wonder if this will work for watching SNF?
I also think that the player on the east has an advantage as their northern cutoff is a far wider area and harder to control by the player in the west.
If you select browse on the COH2 steam directory you cannot step up out of Program Files (x86), I have my steam on d: so I cannot access my installation.