dgcpaphd

I have a flight through LHR arriving Wednesday. Today I received an e-mail from AA which reads:

AAdvantageŽ Executive Platinum Number: XXXXXXX
Our Arrivals Lounge in London Heathrow (LHR) Terminal 3 will be temporarily closed during your upcoming trip. We're working to bring you an all new lounge experience later this summer.

We invite you to enjoy complimentary access to the British Airways Arrivals Lounge in Terminal 5 in the meantime.

Here's how:

Fully exit immigration and customs in Terminal 3
Transfer from Terminal 3 to Terminal 5 using the Heathrow Express (free for all travelers)
In Terminal 5, take the orange lifts to the first floor
Present your eligible boarding pass to gain entry
__________________________________________________ _______

My question is, why would AA recommend that I go to Terminal 5 to use the lounge of BA? I have a connecting flight to Vienna and will not need to clear immigration or customs in LHR. It seems like a lot of wasted effort to clear Immigration and customs just to go to a lounge in a different terminal. Wouldn't I also have to clear security after returning to Terminal 3?

My AA flight arrives in Terminal 3 and my connection is also in Terminal 3.

Is there a decent lounge for One World EXP in Terminal 3?

Thanks