Same router with same antennas!
The P is just a little bit updated version of the internal components (as far as I understood).
If you are interested to update the performance with different antennas, you should search the forum. But do not expect magic improvements (it could be even the opposite).
Some hints:
- The antennas need to be capable to support 2.4 GHz and 5 GHz at the same time
- The higher the dBA value of the antenna the more narrow it sends the signal (to cover more distance), but it's not good in all directions and could be an issue on some areas of your home/flat.
- Uni-Directional antennas can bring great performance if they are used wisely (see here for details of my evaluation)
- And: Do not forget to update the antennas of your devices to meet the higher range on the client side as well!