i was looking at them years ago and heres what i found.
depends what size and where your fishing, g3 compared to xpress.
g3 has alot nicer interior, console, deck arrangement, storage options but the biggest model only holds a 135 or 150.
xpress has a better shape that keeps you dry and holds alot bigger size motor, but the seats and console are cheap.
i know the boats 19ft and bigger hold anywhere from 200-250 and im trying to remember where i saw a 300 on one.
xpress is probally one of the fastest aluminum boats and be the better option of the 2 if you decided get a jet.