I'm not too happy with BMWNA myself at this time. My sway bar links were worn after 62k miles, and they refused to cover them under my platinum extended warranty because they considered it to be "normal wear and tear"!
and that allows them to deny coverage. Fortunately my dealership stepped up to the plate and "goodwilled " it because i have 3 BMWs, (2 M models).
I too am considering switching back to Porsche, or going an entirely different route with a Cadillac CTS V.