a few of those "gripes" apply to all E70s.
Sport seats I'd imagine would work better for you on banked roads doing break-neck speeds (ie. 270-degree highway on/off ramps). It's not hard to get out of them after a few times... take advantage of the inner part where there's no lip to hop. Tailgate half-auto isn't a problem, hardly open the bottom lip unless I'm throwing something big in there... groceries, duffels, etc. not so much. Steptronic is pretty good about letting you do the shifting.
Glad to hear it goes like a beast. I can only imagine what it's like having double the power of my 3.0si. Does the throttle really respond instantaneously or is there a small lag like the rest of us have? I guess if you're in manual mode the whole time then you can't really say.