I think the best thing to do in your situation is to throughly test drive the exact model you've ordered and see for yourself. Raise your concerns with the dealer and then see what they say.
If there's no judderring on your test drive, and you've bought your concerns to the dealer, then I'd say that you'd be perfectly placed to reject the car if it shows theses "characteristics" on your vehicle once delivered. But that works both ways, if the car you test drive does judder, then it's a choice for you to either cancel the order on that basis, or accept the car and never speak of it again.