You may get better suggestions in the AY+ forum, since I suspect there are more people there that are familiar with both programs.
To start with, you could have a look at the following threads:
More important than the destinations you fly to, is what airline you fly (marketing carrier within oneworld), and which class of service and ticket type you have. Also what you want out of the loyalty program makes a big difference (upgrades, awards, tiers, ...). AY+ points are best earned on AY-marketed flights with either Value tickets in Y, or any J ticket. The best use for AY+ points is IMHO upgrades on AY flights, but if you're already flying in paid J, then this may be of little use. I don't have much experience with BAEC, other than using Avios for short-haul redemptions, for which they are good value.
I would recommend plugging in the details of your past flights, or perform dummy bookings for upcoming flights, into e.g.,
Where to credit, and see how many points they would earn in the respective programs. If you can reach a higher oneworld tier in one program than the other, that would probably be the one to choose.