Alright so I want to post my conclusion from my experience to hopefully clear up some of the mixed reviews about the Q300. My experience and the experience that some other people have had with this exhaust on hatches has been that it can be very loud, especially at low rpm... with bad drone. The slots in the exhaust are bigger than the bolts that are used... which gives you some wiggle room. But this also means that you can bolt it up with a leak-free seal, and not have each pipe perfectly aligned. Today I realigned everything, this time making sure it was absolutely perfect. This made a huge difference. The exhaust is much quieter now with no drone. Its exactly what I expected from the start. Its still louder than stock with a nice rumble... but definitely something that you can live with as a daily driver, and that your passengers shouldn't be complaining about.
So lesson learned... if you have this exhaust and its droning or its excessively loud, it shouldn't be. Make sure each pipe aligns perfectly to the next one.