What I've found though a great deal of research and trial and error is that soaking, not soaking to get the best condition is dependent on many factors. If you think about it if the moister of the wood was critical, why wouldn't you smoke with green wood. Though some green woods give off a more acrid smoke.
First is the type of smoker you're using. What you use will change how you smoke things. If you have an indirect smoker, like a barrel with a side fire box you can run a hotter fire because you are not applying direct heat as you are with say a grill, vertical barrel or electric smokers. In my view it's useless to soak the wood for indirect smoking. The quality of the smoker is also a factor. A poorly made smoker which air flow control is inconsistent will make the job of controlling temperature more difficult. Soaking might help initially, but as it's been mentioned the wood can dry out fairly quickly and flare up causing inconsistent temps and inconsistent cooking. If you are having this problem, you have to tend the smoker more frequently. I like to keep a spray bottle nearby to quiet any flare ups.
Then there's the format of the wood. Logs and large chunks will not absorb much water unless you soak them for a long time, days even weeks. Don't forget, this is wood which has been dried and is quite hard. The cell structures have been fundamentally destroyed and are less able to take on water. Construction lumber is dried to make it more durable.
Now chips and small chunks on the other hand almost have to be soaked. Chips have a great deal more surface area per volume, meaning more of the surface is exposed to heat as compared to logs or chunks. This makes them burn very fast and hot making it harder to control by airflow alone. Chips, because of the increased surface area will absorb more water which keeps them from burning up.
In the end, when smoking you have to adjust the processes based on the equipment, the smoke medium and the desired result. This is why professionals that prepare smoked foods will seldom vary the recipe and the method.