As a not quite 20+ year ACAD user, I can also vouch that the learning curve for Revit is greater than ACAD. With ACAD you can basically tell someone how to draw a line, a curve, and text, and they are off to create drawings. A little more involved with Revit. I am at my second firm that is in the Revit implementation process, so my teaching experience (and patience) has grown over the last few years. Every training excercise and book you can find will be helpful, but the best tool is to sit down with it for a week and begin to learn how it wants you to work with it. I also agree that the comparison between it and ACAD is not quite the essential element, as Revit is the next step in architectural documentation. Slowly ACAD will be phased out of offices, and Revit, or in a more general sense BIM, will become the norm.
My best advice though is to keep plugging away at it. You will get frustrated at times, and begin to think that it is much more difficult and cumbersome than CAD, but once you get through that, your opinion will change and you will start to think that any type of simple CAD program like ACAD, Microstation, or the like are barbaric in comparison.
just my .02
