I think you have to put this in perspective. Yes they are different, however, this is not an OTS 2554R. It has a custom 11 blade fan, and if you look at the graph supplied by Mountune, it is saying 275, my buddy in Raleigh just got the 2nd tune from Randy at Mountune and he is knocking on 300/300 on 93. Their waiting for the temp to come down to the 70's to do another run. Being the only car out here over 175,000 miles, I have a lot of driving on this car, with a stage 3 setup. All of the torque down low is a lot of fun,......fun spinning the wheels that is, blowwing off rubber, lots of torque steer. I guess fun is in the eye of the beholder. This turbo pull s like freight train all the way to 7000. And you can drive it. The way it spins up it is so much more manageable than my current setup and in my opinion more fun to drive. Im not saying the x47 or DHM's setup are bad, they each their place. This one was configured and designed by a company that has been doing this so much longer than the others and they started with a housing that had been around even longer. Sometimes you just have to go with experience. That doesnt mean the others are not capable of delivering great product. There are lots of customer reviews about how great their products are. But when it comes down to it, if your making 300 ft lbs of torque at 2500 rpm, and its not a rear drive car, you are having to manhandle the car. The mountune graph is the nicest smoothest looking turbo graph of everything that has been put forth so far and from a company that has decades of experience over everyone else in this segment and this brand. I had an x-47 right here, and I sold it and went with the Mountune.