What do you like best?
I find working in a 3D space to be extremely helpful in understanding what I'm drawing and how it's supposed to be laid out. Not to mention it's uses in navigating a tight space or when coordinating with other disciplines on a project. I also very much like how smart the component systems can be. For instance, if I need to move a particular pipe, duct, etc. then the pieces connected to them will automatically move with them, no more having to use a Stretch command to force everything to move together.
What do you dislike?
There are still some limitations to the software. There's still no support for importing PDFs like there is in AutoCAD. Creating custom equipment can be frustrating as the line drawing system is very limited, and doesn't always allow adjustments the way you want it to. Shared Parameters for family models can be confusing and frustrating as well when an adjustment is needed. Drawing sloped piping can be particularly tedious and difficult, ductwork even more so, as Revit clearly favors straight lines and can end up overriding any sloped systems to be straight just by making small adjustments somewhere else. Finally, there's no backwards compatibility. You can save a model to a newer version of Revit, but there is no saving to a previous version, so you have to be very careful with that.
Recommendations to others considering the product
Revit can be very useful and add a lot to what you can deliver in your project. But it can take some time to learn, and the cost of that to your company and your customers may not be what you need if you're not going to be using it consistently for projects. Also, be sure that if you are working with other disciplines in coordination, there won't be different versions used. Newer versions of Revit models can not be saved back to older versions like AutoCAD can do.
What business problems are you solving with the product? What benefits have you realized?
With Revit our drawings are being created faster, and more accurately. Though there is a learning curve to Revit, its smart systems can make drawing and refining plans easier. And as the industry moves to more 3D modeling and multi-discipline coordination to save on field work hours and materials, we're staying competitive.