.26 is a picco (Same thing as ofna/picco outlaw .26) , pretty good quality and good power. If you purchase this engine, you need to be good at tuning. I have heard many stories of people who are not really good at tuning who are less than happy with their wasp .26. I have heard that the .28 is not as high of a quality engine, and it has some problems as I too have read on www.teamorion.com on their forums. I plan to purchase a picco .26 myself soon. I have had only good experiences with picco engines.