the biggest is that you dont have to worry about the stockers breaking..also you get a more constant boost due to no expanding. and the plastic likes to hold the heat alittle..and the biggest reason i think people buy them is they uasually look cool..
There is no benfit over a FMIC other than cost savings.
I have one hardpipe so I could run a Greddy types S. While I love how it sounds, I wish I had saved the rest of the money and gotten the FMIC to begin with. I spent about $400 on mine and when I get the FMIC I'll only be keeping about $220 of it (the greddy and the couplers) everything else will just get thrown out. That's about $200 - enough for a downpipe/spipe or 1/3 of a full exhaust system.
So if you never plan on upgrading but want a BOV then go for it. If you EVER plan on upgrading I would just wait until you can afford it all. I wish I had.
