Originally Posted by GeorgiaTech335coupe
1. over-simplified answer is yes, but will it be enough that it will adversely affect driving - no
2. No because the exhaust manifold that feeds the turbo on the n55 is too small to reuse on a bigger turbo. You have to provide a new exhaust manifold for either so it's the same amount of work.
If lag would not affect drivability, cars would come with big turbos from factory (also enabling smaller engines - better MPG). Quick response is the only reason for mass market and manufacturers preferring small turbos.