-The advantage touted by users of the fog is always exposure protection. In fact, the best use of water delivery is in fact, to knock the fire down. exposure protection is general speaking, not effective use of the water and the tactic general doesn't work well.
-The absolute advantage of the straight tip nozzle on a master stream is that massive amounts of water are delivered; which is in fact the goal of master stream operations. Straight tips deliver much more water than a fog nozzle, can deliver the water further and with less pressure required from the pump supplying the elevated master stream. Run the numbers yourself. If you're doing the math properly there will be an absolutely huge difference in solid vs fog with the solid bore nozzle being the clearly better choice.
-Keep in mind that the the goal of a master stream is to deliver the largest amounts of water possible.
The above is right on! Smooth Bore nozzles are less effected by wind and deliver the goods. There are just a few instances where the combination fog nozzle may be desired--Rail car incidents, better cooling affect with fog IF no wind and within reach of an effective application.
Remember to remove stacked-tips ahead of water application and choose tip-size based on the maximum water that can be delivered! I've seen too small of tips left on because folks get in a big hurry--I tend to choose one-size larger than I think we can supply and it seems to be a good way to go.
In the suburban setting I prefer the combination fog on our ground-based monitors for two reasons--The first is the winds at ground-level is easily delt with normally, and the combination is very effective at "going back-and-forth" between fog for cooling an exposure briefly, ember control, and when the seat just can't be reached well, whether a ground-based position or elevated position or not.
I tend to gravitate 75% of the time to smooth bore nozzles for "everything!'
Bricault is absolutely correct! I would also like to humbly add that at 75 ft in the air with a fog tip one would lose alot of the stream to wind and by the time the water actually hit the fire it would probably be more steam than water anyways. We are also in the plans to switch our tip from a fog to a smoothbore for penitration, higher gpm and less psi, and reach. I am a firm believer that the best way to protect an exposure is by putting out the original fire.