Too much flow through the engine at this altitude might actually slow you down a bit up here and push torque higher up in the rpms and we need all the torque we can get the 2900lbs moving if you really want to see a real world diff.
IMO save your money or buy a turbo ST if you want to defeat the altitude a bit.
'12 Focus Red Candy SE Sport 5 spd
'11 Subaru WRX STI Hatch
'10 Lexus RX350