The main difference is one of the process -- how easy is it to get the print you want using split-grade vs. conventional VC printing? This is more an issue of psychology than it is of physics or chemistry -- how do you learn, how do you perceive, how do you solve problems? Many of the posts in this thread have reflected this, but I want to make the point very explicit: It's about psychology. This is just a matter of personal preference or idiosyncracies of how different people think or work in the darkroom.
My advice: Try both methods. Decide which one you prefer. Use it, but understand its advantages and disadvantages, and be prepared to use the other method if you think it might be superior for a particular print.