Of course there can be a performance benefit. It all depends on the application you're intending. 4 strokes won't rev as high as a 2 stroke, but it will swing a larger prop due to having more available torque. Larger props are more efficeint than smaller props (more thrust per rotation). They're also less noisy (both larger props and 4 strokes).

One of the reasons so many of the pattern guys went to 4 strokes was that the larger props gave them more control over their speed on the down lines. It can act as a brake, slowing the plane.

If you want some more detailed and perhaps aggressive opinions, do a search in the engines forum.