hi there. Loads of debate on this topic from what I've seen
- Some will say the BOV was put there from factory for a reason. To safeguard the turbo from compressor surge / spinning the turbo wheel backwards, thus wearing out the turbo and damaging it, and that it should always be in place.
- Others will debate it's fine to run no BOV, and they've been doing it for a long time with no damage at all - and I believe there would be a lot of people who wouldn't have had an issue
Truth is, I don't think you'll ever have a straight up 100% answer to be honest. There's just too much opinion in each direction.
So the way I see it is simple. Be prepared in the worst case scenario..
If you feel that you like the sound so much, to the point you'd be prepared to POSSIBLY, down the line, replace your turbo with another second hand one from a wrecker, then leave it as is. You may never have to do this ever, BUT, you need to be prepared for the possibility you might. Worst case scenario covered
Otherwise, don't do it. If you're in the mindset that you never want the cost of replacing the turbo, better safe than sorry would apply, and I'd put in a factory plumb back BOV. Don't get me wrong, your turbo could fail from something completely different and need replacement, however at least you won't be blaming the lack of a BOV for it
There's some more info on it here, but again, this is a company who sells BOV's
http://www.gfb.com.au/tech/tech-articles/11-the-truth-about-compressor-surge