I have heard the D&Ds as well, and I like them, but I think the more docile sound is going to become my preference. My straight pipes were so loud and I never realized it until I took the time away from my bike.
So I am going to most likely go with Muzzy pipes. A few other members mentioned the bang for the buck value, and since my bike will never be a show bike (I am like CharlesBusa, if you can wash it, you can ride it), I am not overly worried about much outside of performance and a good ride.