I ran my 17.5 last night for the first time and I thought I would share my opinion on it. It sounds like most people here are most concerned with performance. If thats you, then this is your motor. Its got punch, low end, top end, and everything in between. Doesn't get hot either. For those of you who want performance and a motor that looks like the bees knees sitting in your car, you might want to look elsewhere.
The issue with attached sensor harness has already been discussed, but thats not my only issue with it. The six sensor wires are six different lengths so its nearly impossible to bunch them up neatly. Whomever is measuring those needs to be fired. The wires themselves feel like they are made of solid copper, they might be, but they're very stiff and feel like youre going to snap them in half trying to fold them over to look neater. And you have to do something with them because they are so damn long. I drive a Type R, my motors in the back and my ESC is in the front. Even with that layout theres about at least 1 1/2" of left over wire to deal with. If your motor and your ESC are very close together you would have the biggest birds nest full of wire you've ever seen. I know it has to be long since its attached to accommodate all cars, but its excessive.
That end of the motor also looks very plasticy. Looks like the designer took his cues from the new Traxxas brushless. I think the old Orion Vortex was about the sharpest looking brushless made. It looks like it was machined by Hudy. Hacker should go back and look at that one and take notes. That plastic cover needs to go. And a timing ring added at the same time. These are just my opinions, feel free to bash them if you like.