Traditionally, BOV's are fairly useless on Subaru's as the stock BPV's do a pretty good job of holding boost and won't throw off your AFR's when letting off the gas like a BOV will.
I've owned two fairly heavily modded Subaru's.... '04 WRX & '06 STI.... typically, heavily modding most cars results in problems. FYI, the 5-speed gearbox in the WRX is rumored to be built out of old cereal boxes & newspaper lol. I broke one myself on the stock TD04-13T snail, and have 3 close friends of mine that broke theirs as well... I seared all the teeth off of 2nd gear back in the day, and I believe two of my friends destroyed 2nd as well, the other busted 3rd.
Those motors have unequal length fuel lines & exhaust manifold runners (headers), leaving cylinder #4 running a bit hotter than the rest (verified numerous times on Nasioc via EGT sensors), and under light detonation, are known for cracking ringlands. So, be safe, do your homework, and don't think that just because your MS3 is gone that another platform is magically "problem free", as Subaru's have their issues as well.
With that said, if you're not too heavy on the mods and drive responsibly, Subaru's are generally pretty reliable.
I'm just curious, why the 2008? Just got an awesome deal on it or something to that effect? As somewhat of a Subaru aficionado myself, I likely would have went with either a 2007 or a 2009; the 2009's got a plethora of huge upgrades from the factory, namely a bigger turbo/significantly more power & much sportier suspension. C&D actually ran the 2009 WRX faster around VIR than they did the 2008 STI if that's saying anything to you. Either way, I'm sure you'll have fun. Congrats on the new car.
