Has anyone any experience with the RB-991 and RB-1080? My research suggests that the only difference between the two is the 12v trigger input. I can get one here for about half the price of the 1080. My concern is whether the 1080 actually sounds better. On paper, the difference I can see is the damping factor being >500 on the 991 and 1000 on the 1080. Other than that the specs are very similar.