From experience, PE middle seat offers much more sideways room than an economy seat. Not huge by any measure but heaps more comfortable. I'm normal build and to me, Y can sometimes be a bit cramped but PE width is perfectly sufficient. It's the seat pitch (depth) that gets me in both cabins when the person in front reclines, though in PE it's much more bearable.
One thing that may need some acrobatics is getting out of the seat mid-flight (for e.g. the toilet) when the pax in front have reclined fully. Your fixed armrest vs seat backs in front leave quite little room in between. But if you are able bodied and can twist yourself a little, it works out ok.
Some tech specs are on the Aerolopa site, at the bottom of the seatmap for each plane model and floor (for A380).
Hola > Qantas > Airbus A380-800The Qantas Airbus A380-800 is configured 14F 70J 60W 341M
www.aerolopa.com