As far as I'm concerned both natural and synthetic stones are great and you really can't go wrong with either one so let me be clear on that. The advantages of the synthetic stones is that they cost a lot less than the natural stones do and are often much easier to obtain and use compared to the natural stones available. You also know exactly what grit synthetic stones are and you get a lot more stone for your money as well. Now that's where the advantages stop. In terms of comfort, good luck beating a natural stone. I really can't speak too much about this because I've never shaved with an edge that was honed on a natural stone before, but I am seeing a pattern though. More and more people prefer using a straight razor that was honed off of a natural compared to the synthetic stones. But the natural stones also cost at least double that of what a synthetic costs and it will be 100% smaller than that synthetic stone is:
I really can't wait to find out. Now a natural stone also takes a lot longer to learn, but there's an old saying that I used a lot when I was distilling that would apply here. The slower you go the better off you will be with the final results.