My sig combo has had all those parts you speak of ungraded
I used a self tuning interface as opposed to a chip
so
I don't know if my efforts & results are what you are looking for
I got results that were much better than I expected
I had gained a good bit of experience using the Tweecer on my
previous self ported E7 NA combo
When I first fired up the sig combo ........
it ran you out of the garage with watering eyes from the over rich fumes
it would not idle without dieing at less than 1000 rpm
it bucked & surged big time at low rpm cruise speeds
it would die at most stop lights
it often would die on decell
There were other issues
but
Hopefully from that short list you can get the idea ......
Drivibility was just awful
I was able to adjust things to where it behaved just like a little stocker
Stang in all ways with the exception of cam lope at idle
A sig link is available for an idle sound clip
I could not relate to you about the seat of the pants but you can
look at the hp & tq curves with the sig link provided
like Grady, i experienced many of the none-tuned issues... bucking, CRAPPY idle, shutting off at decel, stoplights, etc..
w/ the help of him, Wes, and a few other guys, i was able to get my car back up to speed. idles w/in a few hundred rpm's of itself (VAST improvement), won't shut off at stoplights or deceleration, and i can run my a/c w/out putting too much load on the engine.
i also did the self-tuning thing. personally, next time around i'm probably going to have it tuned. but thanks to these guys, i was able to get it going.
whichever you choose, do it. i can't imagine having to drive my car w/out a tune.