I just got a Hobbywing XeRun 4168SL 2250kV motor this week and must say it is very nice! The overall machining and build is virtually flawless. The front endbell is held in via 4x hex screws and the rear endbell is captured via 3x hex screws. The motor wires are more flexible and the insulation is also softer and more pliable. Overall, a much better looking motor compared to the previous EZRun 1/8-motors. The motor wires also exit through a black rubber piece almost identical to those used on Neu-Castles. Comparing it to my Neu-Castle, it looks just as nice and many characteristics look very similar or identical. I wouldn't be surprised if Hobbywing contracted the same mfr that makes CC's Neu-Castle motors.
Supposedly these new Hobbywing XeRun motors are 4-pole. I never got a response from HW when I emailed them to confirm that. So far, the specs shown on chinese RC forums and chinese vendors all say 4-pole. I somewhat doubt that still, but am hopeful they really are 4-poles. I haven't had a chance to install it yet, but hope to soon to check out the performance.
Volume-wise, these are slightly larger than the Tekin and Neu-Castle motors since those are 40x68 and this is 41x68.
I'd really like to get my hands on their larger 4274SL 2000kV motor. It's 42mm with the machined-in fins, but I believe it's a 41mm case also.