I forgot silent running. You're right though the battery life sucks. I was looking at higher capacity batteries for it.Isn't noise another factor in the Go's favor (since the UMD drive is rather loud)? I'm surprised though that the Go's battery life isn't significantly improved without the need of a UMD drive.
The trick to using a Go comfortably, and this took me a while to work out, is to not use your fingertips to operate the shoulder buttons. Instead, wrap your fingers around the unit. I have big hands and I find that I end up operating the shoulder buttons with the inside of my index finger just below the first knuckle. When used in this way the horrible, squidgy feeling shoulder buttons start to make sense and the unit is very comfortable to operate for long periods. It just takes a bit of getting used to operating the shoulder buttons that far down your finger.