This hub seems to get better every time I use it and is a blast @48v, pas 5 28.5mph has me spinning out with 48/11 gearing and that's on knobbly 37c x 622 tyres.
Using it at 36v is enjoyable as well, like most hubs unassisted low speed is a bit of an effort with the weight all at the centre of the wheel and feels a bit heavy to 15/16mph. Generally once I'm above 16mph on the flat I'm unassisted and pas is in 0, saving battery mah for steeper short inclines esp around parts of Surrey Hills out Leith Hill way and Holmbury area as well as parts of E.Sx/Kent borders. Also pas 0 helps to increase range and is comfortable to ride to 19mph once above 16mph.
Like the Q128c this small powerful hub is truly better at 48v then it is at 36v and 17a is more then ample for power output. Currently running using 10a 2900mah PF cells at 10s & 13s.
Mileage is over 1k now.