[ksniperfox]

He is trying to argue TTs are superior for any application.

spool time depends on the siZE Of the turbo and how much exhaust is going into it. so if you have 2 enormous turbos on your supra, its going to take all year to spool them up. if you have two smaller turbos, it spools lightning fast, but the size of them limits the amount of power they will make/and the amount of air they flow. less air=less power.
so supra owners put on one enormous t78 which spools a little bit later but it flows enormous amounts of air.

twin turbo vs single turbo really depends on the application and the goals of the owner.
but as far as your friends argument, he is inevitably wrong.

tt for V motors is typically easier in terms of the amount of piping and routing. especially if you want equal length piping.