Now that Greyborg's custom hubmotor is making it's way into builds we can finally see how the cromotor handles. From Zombiess's initial impression it sounds like it scared the crap out of him! It probably doesn't help that he's running the massive hub in a 21.5" rim with a 125v battery pack and a 100a controller. Inside is a video of him hitting 60mph with this setup.
Zombiess describes this setup as a "suicide machine." It'll do wheelies even when already rolling at 30mph, and this is even with the bikes swing arm being extended by 8 inches! Clearly the 21.5" rims are a real winner for torque.
In this thread extending the swing arm is discussed in length.
He's also done some http://endless-sphere.com/forums/viewtopic.php?f=2&t=33847 to his 18 fet Lyen controller to keep it from popping FETs. He's added some thermal management to help cool the FETs and thermocouples to make sure it doesn't overheat.