I'd just opt for anything in the middle (rows 15-17) and if you're right handed, then go for the right side of the cabin as I prefer the little side table on my right hand. if you're a lefty then obv pick the left side.

I'd avoid 11D and 11G like the plague on the A350-900 or 1000. You get to be toilet patrol to see everyone who goes to the toilet and the opening and closing of the toilet door means shining light onto you at all times. not to mention the smells. same reason why i'd avoid 11A and 11K and opt for something in the middle of the cabin.

Mini cabin is good on the 77W