If the intercooler will fit straight on then its a good investment if you dont want to go for a front mount.
Especially if you have the old rubber hose to the IC.
WUZ is right, they are HUGE compared to the WRX or std one, and so they will offer better cooling.
HOWEVER, IMHO you need to rig some sort of shield up for the left hand side as they draw a lot of heat from the turbo and exhaust side. Its not necessary but a great mod if you can do it.
If youre seriously looking at chaing the pump injectors and a remap, and would consider a front mount then dont waste the money on the TMIC, just wait and get a bog front mount.