My wifeÂ’s factory P2 Di2 came with the 5 port, not a 3 port.

Thanks for letting me know. Still wish my bike came with the 5 port for future upgrade-ability, but not going to complain with the sale price.

I upgraded my wife's P2 last night with the bar end shifters. It was dead easy, plug and play. She hasn't ridden it yet but seems like a very nice feature to have.

Remove the 3 port junction and install a 5 port junction.

Truth be told, looking at a new road bike myself and I notice a lot of companies do this. Same bike and the difference between a Ultegra Di2 model and a DA Di2 model is a lot more than the price difference in the groupsets. Yea, some slight changes in the bar/stem/seatpost.....but still no where near making up a difference in the bikes.

What are the primary cockpit differences?

Rudimentary Profile cockpit on the P2 and a decent carbon cockpit in the P3.

I couldn’t tell you as they might change year to year and I don’t track the differences. Generally the P2 gets a low-end aluminum cockpit of some sort and the P3 gets a 3T carbon cockpit. Neither will be particularly good. I’d advise buying the P2 and investing in a good cockpit like an Alpha X

Got it; thank you both.