lol at someone complaining about poor low rpm performance. an upgraded turbo will spool by 3k or 3.5k rpms, that's perfect in my opinion. if you want a mild grocery getter with quick turbo spool by 1.5k or 2k rpms, keep your shitty stock turbo/manifold.
the vishnu single turbo n54 is a great indication of how the n55 will drive. i'd even think the n55 would be slightly more responsive because of the valvetronic layout.
the vishnu single turbo on the n55 will be a beast. obviously, it's not meant for everyone, but the mid and upper rpm performance of that turbo/car will be a monster and i'd get one in the drop of a hat.