No matter the engines, a 911 is way more prestigious than a Boxter/Cayman. It is perceived as a car in a different league altogether compared to the Boxter/Cayman. But I don't think the same can be said about the 335i versus the 328i.
My issue is why can't BMW "throw in" just a little more power? So they followed Audi in the 4-cyl turbo route, and I am now wondering whether they are also going to follow them in dropping the 335i altogether and offer instead a less "pure" M3, just like Audi now offers just a 4-cyl turbo or the S4, at least in the US.