Thanks for the quick reply. The seat was unable to be manually made flat as I think the seat was jammed. I'm not sure if it was this which ultimately led to the power issue (it felt like there was a surge at one point when I was using the chair before take off). And yep it was a round-trip (I've updated my original post to make that clearer).
We are a family of five, so I felt the 80,000 Avios offer was a little wasted on me as realistically I'd never be booking an Avios only rewards flight but rather just use the points to take some money off a cash flight. I priced up a similar flight to see what Avios amounts were required to get different reductions and it seemed that 80,000 points would not give a fare reduction of £450 - so the e-Voucher offer seems 'better' than the 80,000 Avios. Not sure if my logic is wrong in any way though!
I agree with your points and I am leaning towards accepting the offer as I also don't really want to be dragging this out more than it already has - but I wasn't sure if anyone on here had similar experiences or felt taking the Avios was a better route.
Thanks again!