I have Tudor's dune porting.  It's mild but much more aggressive then Trinity's.  There are a few guys doing Q's HRD.  I know for a fact, 500fanatic does the HRD but has added his own touch to it.  He generally keeps the bridge intact but removing it isn't a death sentence to your motor.  A friend i ride with has the no bridge HRD porting and is still on the same piston since he had it done back in 2005.  Yea, the motor needs to be freshen up because it does have visible wear but it's still a runner.  I've raced guys with HRD porting a bunch.  one with a v1 Q pipe (without bridge) and one with an AAEN pipe (with bridge) and consistently beat them both although the v1 Qpipe guy was always a close race.  Maybe the modded Q pipe is giving me the edge? i dunno.  We all run the same carb and reeds.

I've been wanting to go back through my motor.  Maybe get some really aggressive porting done.  But i'm a bit reluctant being that my bike has been extremely reliable.