Up until about 2008, the entire Gibson USA line employed the short tenon/rocker joint. The tenon length was never the actual issue. The curved surface at the bottom of the tenon was the real issue. If you've ever played an LP where the neck was pitched back significantly, thereby causing the bridge to be very high, you experienced the major pitfall of the rocker joint. The tenon should be flat to the body, like you would expect a Fender to be. Not curved on the bottom. Gibson started to fix the issue in 2008, going so far as to include a "keyed tenon" for greater stability, but made too many other changes to the Standard for it to stick. The customer base rebelled, and they issued the Traditional line, with the short tenon/rocker joint, alongside the Standard. AFAIK, as of 2013, all Gibson LPs (with the exception of the Traditional) now have the new chambering pattern, which allows for a "normal" long neck tenon.