Thanks for the replies everyone! A lot of work goes into it but a lot of enjoyment comes out of it.

Buttercup - A larger tank is generally more forgiving than a smaller tank. But, I find it easier to maintain a smaller one as the chores are less overwhelming for me. (A two gallon/wk water change as opposed to 10g/wk, etc.)

That said, the level of difficulty is also dependent on what you want to keep. A FOWLR (fish only with live rock) is easier than a reef tank and a reef tank can be simple or complex depending on the corals and their light/water flow requirements.

In terms of coral, my tank is pretty much full of easy keepers.