umm.. well, I chose the GSR because everyone I talked to here said that you can get more gains off of less mods on a GSR.
They're easier to work with, and they have a sunroof too!
my GSR beats a lot of Type-R's with I/H/E and thats basically all I have too (except the JDM GSR ECU)... but I just prefer GSR, and thats why I got one!