i find the gearbox sluggish too, mostly on kick-backs at low speed. ie, cruising in traffic at aroun 15km/h ill put my foot to the floor as i pull into the lane next to me, but it takes SO f**kING LONG to kick-down that the car i almost cut off has had to brake so they dont hit me. then it find the gear it was after and powers off. in traffic now i use the tiptronic and keep it in 1st so i can perform said manouvers safely.
maybe due to the higher power and torque over the RB25 that it needs to be more gentle with shifting so nothing down the driveline is broken or prematurely wears out?? thats my theory anyway lol
while the car is moving, i rekon the gearbox is perfect - on my car anyway - except for a problem i put it in for last week.