IMO, mistakes usually forgiven with big tank and less frustration to deal with large volume of water rather than small volume water and the result of a mistake will take toll right away in small tank if not instantly and it'd lead to frustration then quit. Another thing is this hobby is not a cheap hobby for long run, you will need a schedule and commit yourself doing that for years to come, research...research and more research
then think ahead about the maintaining schedule you will need to do per week.