Well for me the rMBP's screen and ability to run many programs seamlessly is what entices me, since I often am multitasking various work and creative projects. While my "needed" usage is for grad school, I also am getting into software development, help out a non-profit with web and graphic design, make short films, write, and am involved in various other multimedia projects.
It sounds like a reasonably good match in terms of notebooks. I'd like to know how well it can drive multiple displays. Displaying a desktop doesn't take much. Other things can be far different.