Hi oldmariner -- another fine review! I agree with you that the voiceovers (particularly for Sunny) are very good.
It's intriguing that different gamers are having such varied experiences with the loading screen times. I went back into the game to experiment with this, and I found that the loading times between screens (for me) averaged 12-15 seconds. Using the map added 20 seconds to that time (a blank screen for about 15 seconds, and then about 5 seconds while Sunny ran to the next location). So going into the Options menu and unchecking the map meant that I saved 20 seconds when going from one area to another -- a big savings in time.
So instead of making it faster to get from location to location, the map actually makes it slower. Anyone who is annoyed by this can just de-activate the map in the Options menu.
I suspect that the frustration for some gamers occurs because there are such frequent loading screens -- every time you enter a new area, plus every time you go into a building. If it took 15 seconds to access an area, and then you could explore for several minutes, going into the buildings or various places along the path, the loading screen wouldn't be an issue. It's when you are looking at the loading screen so frequently just to walk around and go into buildings or walk to different parts of the jungle, that the frustration can increase.
My computer has 2046 MB RAM and a video card with 512 MB Video RAM, which well exceeds the recommended specifications. Having a system that is so much in excess of the recommended specs, yet having (what I would define as) long loading screens definitely puts me into that "whiner" category you mentioned.