My family (including my parents aged 70+) flew A350 PEY a few times and we all enjoyed both seats and inflight service. On A359 toilets are a bit far away but on A35K toilets are much closer to PEY cabin.

Once I had a middle seat in middle row of PEY cabin during longhual flight. Of course it was not easy to use the bathroom during the flight but it was seat pitch is still quite good.

If you have access to OneWorld lounge, CX has solid lounges in HKG, while HEL's OW lounges are mediocre to me.