Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
"you have to call BA, no net booking for AA, Alaska etc."
You have to call BA to book AS (or EI); you can book award travel on all oneworld carriers (including AA) on ba.com. The ba.com website sometimes has difficulty displaying award availability on itineraries involving connecting flights on AA; in those situations, if you find SAAver availability on aa.com, you can then attempt to book each leg individually on ba.com, or call BAEC to have the entire itinerary booked on a single PNR.
Back to the OP: for award travel between North America and Europe, using AA miles is almost always the better deal. AA uses a zone-based award system, so you will pay the same number of miles even if you have to connect somewhere. And AA will not assess any fuel-type surcharges on an award ticket except for flights on BA or IB.