I have the Solo Performance muffler delete and kept the stock rear resonators (ours didn't have the front resonator). There is some drone around the 1600 rpm range, but it's very, very mild. It's really not as loud as I thought it'd be initially, until you actually get into the loud pedal (underpasses are awesome). It's fairly tame when cruising around town and I just love the tone. We really like it and, just as importantly, the neighbors are still our friends.
Thanks! still on the fence with it, its nice having a quiet ride haha they do sound good though!