In my view the 6 is good enough that I haven't found any good reason to buy one of the many new (AWD if they make one) cars I have been looking at, including Volvo T6, Audi RS4, VWR36, or any of the Bimmers. It may not be a s slick inside as some of these named but at around half the price of all of those cited plus many more, this does the car a lot of largely unrecognized credit. The only car that has tempted me so far is the Merc C63. But if I had the readies for that without more of a stretch, I'd go for the GT-R. Maybe the 3 is in this place with some owners too.
As someone else noted and I was tempted to say before, I don't really think there is any comparison between 6 and 3, except they share common engines and badge and four wheels. I have the 6 and it suits me. My daughter has the 3 and it suits her. It's not a case of chalk and cheese, its, well, chalk and chalk. That should suffice.
CP_e Standback & PNP; CP_e 3" SS Downpipe; Corksport FMIC with Top-mount K&N filter & OEM Ram CAI; Turbosmart BOV; Dashhawk; Prosport Boost Guage; JBR solid shift bushes; DBA 4000 Wiper-Slot front rotors; Hawk Ferro-Carbon HPS Street front brake pads (@ 69,000km); Sumitomo HTRZIII's in 225/45 x 18