What do you like best?
I don't even know where to begin. Rstudio is highly customizable, allowing you to choose how to display your console, plots, workspace variables, etc within the IDE. The newer versions of Rstudio allow for version control with git as well, which is very advantageous for collaborative projects. Plotting is also easy, and you can easily scroll through your plot history to compare many plots. You can easily inspect your datasets and variables as well. Installation is very simple and takes a few moments. I use Rstudio with my PC and Mac, and I've never experienced problems with either. In addition to an IDE, you can also write latex and markdown documents integrated with R code and output. I love this feature, because I produce many reports in which I need to show R code and output. Also Rstudio is free!
What do you dislike?
Although Rstudio is an excellent IDE, that comes at a cost of overhead. Compiling large lateX documents, for example, takes much longer if you run them through Rstudio versus the command line.
Recommendations to others considering the product
I would highly recommend Rstudio to a wide variety of people--from students to instructors, business professionals, and anyone who'd like to get some programming experience in a user friendly IDE. I especially recommend Rstudio to those who are on a budget, because Rstudio is free! I would also recommend it for analysts who wish to use version control on collaborative projects, because Rstudio integrates with github.
What business problems are you solving with the product? What benefits have you realized?
I use Rstudio extensively daily to analyze, process, and manipulate data. It is an invaluable resource. I would not be as productive or efficient without it. I really love that I can produce high quality reports with R code. This helps others understand my work and makes my research reproducible.