Ok, i've had an rb20det s13 and an sr20det s13. Same diff ratio.
The sr20det still has more torque, even with a laggier turbo (2540 on the sr, 2530 on the rb). The rb20det reved out much better though. It probably has a lot to do with the better suspension in my current s13, but this one handles like a dream, literally jumps side to side on the road, perfect response, whereas the 180 was sluggish to turn. Never pushed hard enough to notice under- or over-steer.