A bigger tank is always better on two conditions. The first is that you can afford it, the second that you have space. More water is more stable, more water will keep cleaner easier, and more volume means aquascaping to your hearts desire.
Harder to clean? Not really, you'll need to deal with more water and you'll have more area to vacuum, but if you get the right supplies it's not a big deal. For my big tanks I use a python hose that plugs into the tap and drains and fills and vacuums the tank without having to haul buckets. My 75 gallon is no harder for me than the 15, and the 2.5 gallon tank is probably the biggest pain of all.
It's a mistake to think just because you get a bigger tank you need to get bigger fish - in fact, if you resist getting big fish just because you have a bigger tank, your fish will have that much more room, and schooling fish don't need to be kept in minimal groups - you can keep real schools, plus a greater variety of fish if you wish. And of course, you will want room for those fry! Multiple small tanks might be a good idea if you plan on continuously breeding to sell, but otherwise it's much nice to have one splendid larger one.