Bill,
It is a fantastic cabinet. It is very solid - no rattle, shaking, swaying, creaking, etc... Just confidently projects what the speaker is doing with that classic familiar design.
I'm quite happy with my preamp/amp/cab/speaker situation at the moment.
I don't know the exact weight, but I can tell you the shipping weight of an unloaded SSP Quarter is 18 lbs., so the cabinet is probably in the 16.5 - 17 lb. range.
Of course, with the mammoth Beyma Liberty 8 I have front loaded, it puts it on par with my Groove Tubes Soul-O 45 combo, but with a completely different tone.
The one thing about having the Beyma in the cabinet is that it does make it somewhat front-heavy, and it would not be a good idea to have the cabinet angled on an amp stand. Instead, place it solidly on something that won't tip forward (I use my effects rack, which is a 10-space Kriz Kraft).