Looks like OS is filling a niche with a .60 size 4 stroke that's designed similar to a really popular engine. Looks promising.

http://www.osengines.com/engines/osmg0898.html

If this was a Chinese knockoff I wouldn't give it a second look.
OS doesn't make junk. Unfortunately they cater to the pattern and large scale R/C crowd. They're quite capable of making a world class stunt engine if they thought there was a market, hence their entry into Electric. Which I believe is the future.