I have not had mine long enough to say about battery life though that is dependent on how much you use the light (BTW it has a wonderful feature that when you move your wrist to look at the time it has a sensor so that if it is dark the light will automatically come on!)
I also have a solar and atomic G shock, a 25th anniversary model and I love the way the display is more gold in colour on that one but it is a more classic g shock shape.
The mudman is stunning and I much prefer the older style to the new style. BTW the olive green one the other poster is on about is, to use a quaint old British expression from the old country,"THE dog's Bollox!"
This is an image of the GW5525A-1

This one is my standard for all the others when it comes to accurate timekeeping as it is atomic! I love this watch!
One last thing, one of your fellow countrymen, Sjors, is the acknowleged king of Gshocks, he has a website dedicated to it, a great fellow, you might want ot get in touch with him for more info!
http://www.g-peopleland.com/