If new to disc brakes, the fairly obvious warning of being wary on wet pavement and loose surfaces of especially front lock up. One really needs to practice emergency braking over and over on different surfaces to get a feel for more powerful braking systems and to be more sensitive to finger pressures, especially at harder applications-- opposed to rim brakes, you have to watch your finger pressures more at the point of strongest brake application.
Always better to set up some planned tests and gradually increase how hard one brakes to get a feel for throwing out the anchors to various degrees.
oh, if you do tour, other than wheels, rack and panniers have different weights, and keeping track of that too can make a difference in total weight a bit too, it at least be aware of when choosing gear.