It has been my experience that large tanks require a bit more than minimal maintenance. It is not so much that you have more too do, it is that you have larger volumes of what needs to be done. Waiting on a gravity drain water change and doing buckets is not the easy-way (nor fast (but not too fast!)) when large tanks are concerned. It gets tedious. Adding a large number of Discus, which require a tad bit more care than most species, only adds to the "more to do" list so that everything thrives.
Personally I would automate the water change and fert routines, shoot for medium light over a 4" thick+/- substrate, have pressurized CO2, have about 2000GPH of filtration and another 2000GPH of circulation, landscape driftwood and some overhanging roots, plant extremely heavily with medium-light/low-light plants and floaters, add 200 cardinals or neons, about 20 bleeding hearts, 21 cory cats, and a flock of 21 discus.
Once or twice a week EI ferts (depends on plant mass/feeding/water source/etc.).
I would expect to change 25% of the water weekly.
Filter cleans every other month.
I would expect a few neons/cardinals to be eaten.
Generally speaking of course.