I keep Discus as well in community tank with gouramies and angels... Temperature, healthy fish to start with andgood aquarium maintanance will increase your chances of success...
In my experience, they are pretty damn robost fish (specially captivity bred fish) and highly tolerant of medications which makes them easy to treat (except for internal infections). Most of them were brough up in Discus only tanks and that I found to be a problem in community tanks. It takes a bit of work to get them to adjust, but once they do, they are fine. how much work depends on the temperment of the fish. The latest batch of 4 I bought, 2 adjusted well and were soon fighting for their food. one refused to eat and one was bullied around and starved for several days. It took me 2 months of trial and error to get them to settle down, but they now seem fine and have taken their place. Enjoyable experience and would recommended to anyone once you have a bit of experience under your belt.