When my new wife and I were in the throws of moving me out of the house I sold, and deciding where we would live, (either in the house she already owned, or a new and separate Condo) we had made a bid on a Condo in town.
I remember that the garage was very LONG (it could literally house two cars and a bike, front to back) and that was appealing to us. But the Condo Association had multiple Speed Bumps on all roads that I wouldn't be able to ride aroud, and of particular annoyance, were the ones on the uphill grades, leading from the area where our Condo was (and I'm sure there were other Speed Bumps in various places in the complex).
I also remember considering the quietness of the Condo complex, and wondering how receptive my fellow residents would be to my Harley, which has after-market pipes. They are not short pipes, and on a loudness scale, I am quite confident they are tame compared to the pipes you have described that you have on YOUR bike, but still..........
In my opinion, you did the right thing, by entering into a conversation with your neighbors about it. That breeds good blood between you and them, providing you kept your cool, and tried to show cooperation, which it appears that you did. That's a good start.
Obviously, when buying pipes for effect, whether to make a statement or just to enjoy the heck outa the sound, there is a downside. Some States have Laws that (and I'm sure you probably already know this, but anyway......) can get you ticketed for overly loud pipes.
Of course you don't want to have to change out your pipes; not only because you like the sound, but because of the hassle and cost of doing so, BUT..............perhaps you could call it a "lesson learned" and do that anyway at your earliest convenience. Unless of course you are planning on moving soon, but even then.........your NEW neighbors might give you the same responses.
Being conscious of our impact, (like the old thing about not leaving your mess behind in the woods) and being conscientious about it, is always the better choice. In the long run, how we respect our neighbors will come around to either bite us, or help us on one day.
“Just because you CAN, doesn't necessarily mean you SHOULD!!" -SDC