I've never owned my own picco .26 but i have used a few of my friends and they are just raw power. super fast and well suited for the revo
the os i have owned and from others that have owned i think it is the better choise for racers. its got a 3 tuning needle and have heard they last a long time. it is also a direct drop in for the revo or maxx. no motor mount needed but they are more expensive if i remember correctly
i would say if your going to buy brand new the picco is probably the better pick cuz its cheaper, but if your going out on the race track, there nothing better than an OS IMO