I fitted the Woosh XF07 front hub to a Viking tandem a bit over a month ago. Woosh suggested the SWX02 48V 250W rear hub kit but didn't have it in stock for 700/622 wheels then. They do now I think (at least they are advertising it). The XF07 helps with the hills around here (Winchester, not too extreme); we generally use level 2 (of 5) assist and level 3 on the hills and it does all we want of it. We are getting around 35 miles per charge on the 13aH battery.
We are very satisfied. If I were fitting now I would probably get the SWX02. Battery only 12aH, but as it is 48v that is equivalent to 16aH 36v battery.
I have had an issue that the rim that comes with the XF07 rim does not like my Marathon Plus or Marathon Plus Tour (you may have seen http://www.pedelecs.co.uk/forum/threads ... lus.32147/
) Could be my fault, but I've fitted these tyres on several bikes before. (I suspect you are in touch with them, Tony just accidentally called me Simon in a reply on that forum)