Seems rather silly to post a review of a "stock part", but since intercooler mods are becoming more common as are JDM parts, why not?
Cost: Usually run $500-700 through Vendors. I got mine for $350!
Fitment: Open hood, bolt it up. It's that simple. The only modification I had to do was to move the AC line aft (towards the trunk) slightly for it to fit.
Size: Roughly 1" thicker and 1" higher than the USDM STi intercooler.
Why: The USDM STi intercooler is nearly the same price. The USDM STi intercooler has fitment issues. The USDM STi intercooler is smaller. To sum it up, there is no reason in the world to use the USDM one rather than the JDM Ver 7. If you think of a reason other than a good deal, let me know.
Performance: No dyno data sorry, but some butt dyno and hard data results. Butt dyno says it has gains. Previously, I installed Borla headers. While I think they were a super
mod, I did lose a little boost with them. After talking to Cobb Tuning, they said this was very common when using headers. After installing the JDM intercooler, my boost returned to normal! I assume this is because the JDM intercooler has a lower pressure drop than the stock unit. Either way, I have a remarkable improvement in performance due to the intercooler and new found boost.
Recommendation: While I wouldn't recommend that a stock or near stock car get a new TMIC, I would say that this unit is a good upgrade for mid/highly modded cars. It is beastly cheap compared to other near $1000 TMICs, and as many Subaru parts go, there is no proof that their higher price tag nets better results. Even if you don't like it, intercoolers really lose little value compared to other mods. Sell it and you will probably only be out your shipping costs.
Hidden cost: As with any TMIC, you will get the best effeciency by using a bigger hoodscoop, air splitter, and water spray. As soon as I get all my parts in and resolve any/all fitment issues, I will update this post with the OEM part numbers for 04s. If you have an 02/03, you will have to do some searching.