Nikon Speedlight SB-800
Plastic Fantastic, then again, I wouldn't want the flash to be any bigger or heavier, so the use of plastic is actually welcome, since it keeps the weight down. The unit is well constructed, and there are no strange creaking noises that are common among cheap plastic products. Compared to Nikon's other flash units that are currently on the market, the SB-900 and SB-600, the build quality is about the same.
Easy of Use and basic operations:
On a scale of 1-10, I'd give the SB-800 a 7. I give the SB-800 a 7 because the user interface could use a face lift, but that came in the form of the SB-900, which is much simpler to operate, from what I've seen of it in the local camera shop. Most of the functions of the flash are in the menu system, which is pictorial, and somewhat slow to use. The basic functions such as zooming the flash, and adjusting flash compensation are easy to accomplish via the D pad on the back of the flash unit.
The unit normally zooms from 24-105mm (FX/35mm) with a flew presses of the zoom buttons. That range is extended when you use the built in defuser or the included defuser dome, which allows for up to 14mm wide angel usage. The mode button allows the user to quickly change the flash settings from iTTL (with or without balance fill flash), Auto, Manual and Repeating Flash. There is a small red "flash" button which allows you to test the unit. On the top of the unit, right under the flash head itself, there is a modeling flash button, which helps you to see where the light from the flash will fall before you take the shot (using this extensively will drain your batteries quickly).
Once you are in the menu system, which is achieved by pressing and holding the Select button (SEL on the unit), you can change various settings on the unit, such as the backlight, off camera flash settings (commander mode, SU-4, remote flash controls, etc), power saver (standby) time and more. Most of the time I use the SB-800 either on my D300 or remotely via CLS, as I do not use PC sync ports to connect the flash with other speedlights off camera.
Battery life depends on a number of factors, such as distance to your subject, the ISO sensitivity used when shooting, along aperture and shutter speed. I can easily take a few hundred images without any battery power issues. I can often go for weeks without recharging the batteries, but I'm not a heavy flash user. I cannot really compare this to any other modern Speedlights since I have not used any others enough to do so.
Comments and conclusion:
I like the SB-800 for the flexibility of off camera flash, via CLS (CLS = Nikon Creative Lighting System) and the ability to take pictures in dark conditions without having to pump up the ISO on my camera, and even more so in situations where doing so would not help. To be honest most of the time this flash stays in my bag, I shoot with natural light 90% of the time, as I do not light the added weight on top of my camera. Also I find the flash can startle birds and other wildlife, so I avoid using the flash unless I have few other options to get the shutter speed that I need. That being said, I am very happy with the SB-800, due to the flexibility it offers for indoor shooting. I like using the flash gels that come with the unit, as they allow me to add colour to the light, which creates a different feeling than the standard pure white light. At some point I would like to add second flash unit, most likely an SB-600 or other mid-range flash unit, rather than the SB-900, which to me is much to large. I think the only reason I would buy an SB-900 would be if my SB-800 died and Nikon could not fix the unit.