I would agree with 2 piece here.

The Lasers were designed for scale applications. They are very smooth and produce very little noise, wich in addition can be muffled very well because these engines seem less affected by muffler backpressure then others.
They do have a little less power then an OS or a Saito, but they generally can swing a larger prop at a lower rpm, wich I would call a benefit in a scale application. Their power curves are much flatter then other high power four strokes, so power will remain pretty constant when operated at a lower rpm.