its pretty solid - i used to run it in my NTC3, but have since moved it to the GT and put an OS .15cv-r in the NTC3. although i like my OPS - stick with the OS mill's. i usually will only go that route, but tried something new and got a Rossi pixie black, and that OPS. the rossi is stupid quick but one of the hardest engines i have ever had to tune. the ops has been very reliable, 2 gallons through it already, but runs pretty hot (260-280) and doesn't have alot of low end grunt.