I have owned several Taylor 12 strings all jumbo models. 355, 455, 855 and the W65. I don't have a problem with the size of the jumbo. I thought they had great volume and marvelous tone. The 455, 855 and the W65 I had were spectacular.
But if comfort is an issue I would look at either GS5 or GS8 12 string versions. I am not a fan of maple for it is too bright for my tastes.