I have such a engine, and it's clocked in at 653h at this day, at 500h I did an check off the valves and canshafts. They did not look like they have been used at all.
I exspect this engine to last at least 5000h The way I use it.
It's used in an searafting RIB, running mostly at 5000rpm or higher. THe only thing I do for it is following the service at each 100h, and only using high quality oil and lubricants.
So take it easy and run the engine hard, it's made for running at high rpm's. But it's very important to have the right propeller on it, so it can run at optimum rpm.