Austarion

Hi, seen mentions of fitting other turbos in place of the standard unit, s what i'm really asking is; does it spool up quicker/later? make a noticeable power difference etc? thanks

Depends on what kind of power you want and where.
There are 16 and 20 G comp wheels or if you have or are getting a new manifold then a Disco Potato is a very responsive turbo or a GT3071 will give a higher top end powerband.

Mitsu turbos r excellent top shelf performers and have most power craves covered, up to the 20g

a 60 trim T3 is roughly on par with a 16g.
The biggest advantage of the t3 is when/if you have the source of a low budget upgrade to a t3/t4(numerous sizes)
GT series r hyped up and perform no better

take the overrated potatoe for example. Introduced at $1100. A $500 evo III 16g would slap its head off