T4i to 6D

I think I might be growing more confused ... One can spend hours reading camera opinions. Perhaps I ought to unload my EF L (the 24-70, first generation, f/2.8) and just get the 15-85 EF S, keeping the T4i. Would that really work better than the 24-70 because it's designed for the smaller sensor? (I a,m reluctant, however, to accumulate EF S lenses; would rather just have two, maybe eventually three, really good lenses.)

My heart wants to plunge into the FF experience. Well, OK, not my heart, my head. My wallet says be careful. My backpack says, do you want to lug this stuff around when traveling? Can't have it all, can we?

I don't want to get too deeply into photography because it can be a distraction when it's not your job. It can be very time consuming and enveloping (just reading the forums can be enveloping ...). Just want to get some really nice family, travel, and also ethnographic shots/video related to my work.

Thanks again everyone for indulging my questions/doubts.