Weight isn't too bad, I haven't weighed them but it seems no worse than my old 8X10, maybe even less. The sound is pretty bass-shy. One of the original speakers blew shortly after I bought it, it has had 4 15" Fender OEM 16 Ohm speakers in it for years. I really couldn't tell the difference in tone when the band is playing. It sounds like a huge guitar cab. Pretty good with guitar actually, with the big Fender amp. It's in the drummer's garage because I have no room for it at home. I liked the Fender rig better with a Carvin 10.2 NEO in place of the Sunn,plus I could put the whole thing in my car.
I loved the Sunn with a distorted Sound City amp and an Exploiter, but clean it leaves something to be desired. The 2 Bag End cabs don't have any highs to speak of, so the 3 sound good with the Fender.
I like having an excuse to show the pic, on that other forum they threw stones at me for owning this stuff, and worse than stones for daring to play non-identical cabs together. No doubt it would be a nightmare onstage with a PA, but that isn't likely to ever happen.