BA tends to be good for shorthaul European awards on BA and bad for longhaul awards or partner awards -- the exact opposite of most other programmes. Also the household account is a big advantage that makes it quite useful for a lot of people.

All else being equal you're usually best off with the programme of your home airline as they tend to be better tuned for your needs. They might have more local non-alliance partners, have more fine-grained award charts for the region, or have more promotions that you're eligible for. But there are definitely variations, some big variations.