I think it's fine the way it is, but I was expecting a bit more (perhaps foolish). I don't like that there are mountains on every side near the coastline, and the most boring mountain for me is definitely Mt. Josiah. There's just nothing on top of it, its only purpose is to 'hide' Fort Zancudo and to create the northern steep river valley. I would have loved it if that whole mountain was replaced with a forest area, perhaps extending the Paleto Forest region all the way to Fort Zancudo. Josiah just feels like a retarded brother of Chilliad. And to be honest, I think the placement of Chilliad isn't that great either.. It definitely does its job to appear massive, but it kinda keeps me from going to the northern side. I also think it's too steep, resulting in only 2 or 3 clearly intended pathways. And to add my last complaint, the Alamo Sea is too big. I liked it at first, but it feels too empty and there are no people on the water. So yeah to summarize, LS is awesome, the Vinewood Hills are awesome, the Sandyshores region is sweet, but it seems that the further away from the city (south-to-north), the less interesting the map is to me.
It's still a great game though!