I plan to update this thread as time goes on. My LS17SE has about 40 total hours of run in time since the SE upgrade was performed, and approx 250 total hours of run in on the unit as a whole. I am certainly not talented with words, so take this for what it is worth. This is my opinion based on listening in the context of my current system running fully balanced connections and includes ARC Ref 110 with KT-120's, B&W 805D's, Bryston BDP-1 and BDA-1 using Audioquest CV-8 and Columbia cabling. I'm very pleased with this upgrade. Soundstaging is deeper and more defined as you go farther back in the stage, though overall width at this point seems to be very slightly reduced. The general ARC large sound field is still present, and I assume this will improve and loosen up a bit as break in continues. The most pronounced change to my ears is the sheer density of tone and notes. I hesitate to caller it richer, as that can imply more tubey sound and that it certainly isn't. The entire range is more there and very rooted in space. The presence of singers and instruments has improved quite a bit over the standard LS17. For clarity, I was not aware this was even an issue or lacking at all until the SE upgrade came into play. Presence was always a strength of the standard unit in my opinion, and this upgrade has served to increase it by a good margin. The bass region has more authority also. Surprisingly, it almost sounds as if I added a subwoofer into the system. Again, it was not previously lacking in this department IMHO, but the density, definition and power in the lower octaves gives the impression and feel that bass improved and was increased. This is just my experience thus far. Hopefully this helps if anyone is considering the SE upgrade. As a point of reference, my Ref 110 has only 151 total time on the clock, so it also is still running in.