Many reactions on the previous post about the Gretsch Baritone double-neck, including a comparison with the great Mosrite Joe Maphis that has indeed a much cooler look and more important has non-parallel necks, that is more organic and allows a smaller body... I just regret that it only exists as a 12/6 and not baritone/6. Also it's long time discontinued and therefore unaffordable.
About why do people use double-neck guitars, if it's just to have a rhythmic neck / solo neck for a song, I'm far from convinced - would be more interesting to develop solos with 12-string, and unless you're Jimi Hendrix ou David Gilmour, solos are so often just fillings that they don't require something so sophisticated as a double-neck guitar... Jazz à la McLaughlin feels more relevant. And I know what to do with one too (but I'm not McLaughlin, for sure).
More double-necks later!