The machine work and materials in O.S. motors is first rate, you definately get a quality engine with O.S. I've had a number of O.S. engines and have never had a failure, when tuned well they last a long time. I have two .21 RGs in 1/8 buggies and a .21 RZ -R in my Proceed and they've been great engines. I've never had a small block nitro but a friend replaced his stock T-Maxx engine with an O.S. .18 and it screams. There are a lot of companies making engines these days but I doubt that anyone has the R&D and tooling that O.S. has.