Yes, you have it correct sir.
I like the N55 too, back to the single turbo.
Once I move up to the DP and IC, then I am debating on how to increase turbo flow. My turbo guy can do the larger turbo wheels for me, maybe clip the turbine side a little, but there seems to be some dis-like for this compressor wheel upgrade.
I have been updating the tdo04-15T turbos for years with the larger 19T wheel and I love how those run.
The advantage would be cost, upgrade the stock Tdo3 turbos for 450 each and make another 50-60bhp, bolt right up, no new parts needed, cost is very low.
Second option is to go to something like the GT 28RS Disco Potato and make a lot more power, cost 1100 each and then manifold and dp mods to make it all work, oil and coolant lines, etc.
I may play with the Tdo3 compressor wheel upgrades first and see how they do, how much more power and how high the egts are and see how they hold up.