Re: Gibson's meaning of "weight relief" and "chambering"
I have several chambered LPs. Two Supremes, an Elegant, and two Classic Antiques. Each type has different chambering. The Cloud 9 Les Paul Historics had a different pattern still.
My two 1960 Classic Premium Plus LPs are "swiss-cheesed", and the Historics are all completely solid. Surprisingly, while the Classic Antiques are noticeably lighter than the others, the 1960 Classics, the Supremes, the Elegant and the Historics all weigh about the same, between 8.9 and 9.2 lbs.
Bottom line: for me, I'm not sure it makes a lot of difference. A good guitar is a good guitar and all of these sound good.
Bill