Gibson claims lacquer increases the sustain on a thick slab of wood? Have they empirically measured this? If so, where are the results?
This is pure bullshit.
Nitrocellulose lacquer is nothing more than a sealant that was invented in the 20's. The hip thing about it is that a
"thin" nitro finish on a good quality piece of wood will yellow and crack over time. This yields guitars with a natural patina and checking that most players and collectors find attractive and desirable.
However, "
thick" nitro over poly can yield cracks instead of "checking" especially if applied incorrectly (bubbles) and not allowed to dry properly. A lot of guitars in the 70s and 90's had thick polyester finishes, Those guitars IMO sound lifeless and have no sustain whatsoever, especially when compared to thin nitro finished guitars.
Honestly, unless you are getting a historic RI, or going for a vintage look, you are better off getting a thin acrylic lacquer finish. Look wise -- both will basically be indistinguishable except the acrylic won't yellow or crack over time.
I am a big Gibson fan and owned many historic and vintage pieces over the years. That being said, their QC over the years has been up and down like a roller coaster, not just with their lower cost mass produced non-custom models, but with their historic RI line as well.
I learned over the years you need to play and examine a lot of Gibsons before buying one. This is not always practical, but it is the best approach. Also there are a couple of Gibson dealers out there ( like
Wildwood Guitars) that actually go to the factory, preselect the woods and supervise the production. Those guitars are about as perfect as you can get.