1. Could they have SOME low level light during the investigations? Since the ghosts are seen/heard during the daytime by their hosts pitch black is obviously just for "good TV." It's very frustrating to hear an investigator say "I just saw something down there" and point down the hallway in front of them and we can only see the 3 feet their flashlight illuminates.
2. Could the videographers actually swing their cameras around the ROOM now and then, especially when the investigators say they saw something "over there" instead of always being on the investigators' FACES?!
3. With the budget they must have by now, could they get more cameras? Which also leads to....
4. How can anyone analyze videotape for visual anomalies that may be subtle when they are watching 4 tapes at once on a split screen. They should have more human viewers or take more days to really analyze their findings.
5. And last, but not least, one night is not enough to declare a site haunted or not. I would like to see the group spend two nights in each location to really create a better chance of experiencing something and catching some evidence.
Although the show (for me) has these shortcomings, I do enjoy it and think it is far and above the best of the ghost investigation shows on TV. 
Any thoughts?
