In general, if you follow the instructions that come with the engine, you won't have any trouble with an O.S. or Supertigre. They both come with the low-end set by the factory, and will start and run well with the top-end set reasonably close (about 3 turns out from all-the-way in). Supertigres do seem more sensitive to the low-end setting, and I've found you can't get really smooth throttle response until they're fully broken in (1-2 gallons of fuel). That may give O.S. the edge in user-friendliness. If you can afford the extra bucks, the O.S. might make a better "first" engine.