Look at the torque curve for your mod settings. There's one on the back of the brochure your car came with. It's pretty flat over 5,000-5500. Not much point in pushing much past that, as all you are doing is generating noise, attracting attention and more significantly, running higher piston speeds than required, the prime cause of engine wear. Select a shift point so the next gear lands you squarely at the bottom of the steepest part of the torque curve, and where the turbo is spooling nicely, so you have maximum pull for the longest time before the next shift is required. I almost never see 5,000 on mine as the bottom end is so strong.
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