takes a long, long time to really understand all the nuiances of the water vapor imagery

it is often mentioned as a tool by some of the better forecasters at the NHC in discussion

it is not used alone but it will often show you what is evolving in different levels of the atmosphere when you move back and forth between other sats and obs

the storm will move in the atmosphere whichever way it is easiest.. as many have said "like something dropped into a stream" so while on IR and VIS something may look tougher than nails or about to erode... the water vapor shows an evolving pattern that will often become tomorrows IR or VIS

And...yes as you said you have to know what to adjust for when looking at it. Because as with most things online "what you see is not always what you get"