I had the 24HP B7S pro in a Conquest but only had it a few hours. It was a strong engine, ran good and quiet. Now I talked extensively with my Simp dealer about it.
He said that a couple of years ago all the tech's (He is One) had complained to Simplicity/B&S that the intek's and new Pro's had avery poor air filter design that was allowing dirt into the intake and would hurt those motors. As a result they re-designed the intake on it and you will that it is much better. It has a rubber cone type filter that fits tightly and has an outside foam prefilter as well. I have a new Legacy XL with a kawasasaki and it has a great air filter, but basically the same .Pre foam and paper then a tight seal. The dealer says that it turned those engines around, that are good and they are not seeing the prior problems. So I do think the Pro is a good engine and better than a Kohler Courage.
However the Vanguard by Diahtsu remains the flagship engine at Briggs, It has a long track record and much commercial use as well. The Diesel in the Legacy is a Vanguard. By the way Kohler Command have a great rep and lots of commercial record as great as well.
So is the pro good, yes I think so. It is not as bad as the original with poor air filter. It has pressure lube, spin on filter. Will give many hours.
So is the Vanguard good, well it is probably great as these air cooled engines go. So you get down to price and longevity. These are usually 1000 hr rated motors. That's a long time, they may both outlive us!
Compare the price difference of the Pro vs Vanguard, is it worth it to you? If you feel better with the best get the Vanguard. If you take great care of your engine, oil change, clean Air filter and it is for home service, the Pro should last a long time as well.