Aquí tienes las diferencias según una web inglesa:

GA3/4E

Detachable speakers under
mounted on GA3,
side mounted on GA4

GA5
Non detachable under mounted


GA3/4E
3 x SCART

GA5
2 x SCART both RGB/ composite-in

GA3/4E
DVI-I

GA5
No DVI. 15 PIN VGA analogue pc-in only

GA3/4E
Standard video chipset.

GA5
New, European chipset delivering extra lines of resolution into picture for extreme clarity. Excellent, judder-free images when picture is moving.

Saludos