fitted it today. the part was fine and the process of changing it over was fairly straight forwards and took me about 2hrs (about 30mins if i was to do it again).
if anyone else finds this i would advise it over a mechanic as its £25 vs £150 (in London). i was able to take it off and fit the new one without removing anything else under the hood, although getting it in and out past the plastic box behind the insulating foam at the top towards the passengers side was a bit tricky.
i have done something silly somewhere though. they work great but for some reason the default postion my wipers return to is now 'up' rather than seating down when i turn them off. anyone know how i've managed to do that?
edit: losening the nut of the rotating part the motor attaches to, reseating the wipers to the bottom, and then tighening it again fixed that issue.