Yes there is an advantage to the 4th blade. But it all has to do with what YOU want out of the boat. If you won't miss about 1.5 to 2 mph, and you like to get on plane faster, hold plane at a lower RPM, run smoother, and if you run the motor high on the transom in choppy waters, you'll like the 4 blade.
I don't race, rarely do I ever go wide open throttle. But I like the faster plane time and smoother running. Holds plane about 200 RPM slower than the 3 blade stainless, and it's 1" less pitch (SS 3 blade 11", AL 4 blade solas 10"). Speed is roughly 2 mph less with the 4 blade. SS would get about 1mph back (verfied-friend has a 10" SS Solas 4 blade that I borrowed for giggles).
If you decide you want one, drop about an inch of pitch from what you already have-if what you currently run is close to optimal. For instance, if your motor's max RPM is 6000 and you're running 5900-6100 RPM already with a 3 blade 10", if you go 4 blade, you'll want to drop back to a 9" pitch for best results.
I also had a 4 blade Solas AL prop on my old 9.9-and loved it on that one as well. The factory 9" pitch 3 blade would not plane the 1432 boat. I dinged it up pretty good and went to buy a prop, and they had an 8" 4 blade in stock, and discounted...so I tried it. And loved it. Sold it with that prop on it. In that case, the 4 blade was faster because it would actually plane the hull.