It might have a quick blast up Shakespeare, John.
My old N54 one was a twin (2 sequential turbos the same size) the same as the 1M's lump. If you're heading for big numbers, this is the version you want. Fully forged internals, fancy valve train and good for 500hp with a few bolt ons, and more with different turbos.
This N55 has a twin scroll, which isn't a little and a big turbo bolted together, it's got 2 inlets being fed by 3 pots each. It's to help it spool faster and reduce back pressure into the head. That's as much as I know about it, but it's pretty much as lag-less as you can hope for, so almost drives like a big N/A but with sh*t loads of torque. I'm not aware of anyone reliably pushing this lump past low 400s.
This may change though, there didn't seem much appetite to push the N55 too far, as anyone who wanted silliness bought an N54 car. Now we're into a new model, they may focus on seeing what this can do?