Bulkhead seats have the obvious pros. But there are IMHO at least two downsides.

One is the usual one that the distance you can slide your feet forward is limited by the bulkhead, compared to non-bulkhead rows. I have in the past moved from 12A or 12B to a non-bulkhead seat to sleep, so that I can stretch out more fully.

The other is that the curtain dividing WT+ from the F galley is right by these aisle seats. Depending on the crew, you can find that your feet get flicked by the curtain all through the flight as they pass through that curtain. Again, this can be irritating if you're trying to sleep. The window seats don't suffer from this, hence I'd pick 12A over 12B.

These problems mean that we aim for 14AB or 13AB - preferring 14 because it's one row further away from any noisy babies that there may be (very rare indeed in WT+).

One other thing: the WT+ toilet is on the A side of the aircraft. If you're on the other side, you have to walk aft and then cross through the doors 2 galley to get to it. So if it's a choice between 11J and 12B, I'd probably go for 12B.