It's hard. But worth it to me. And I completly agree with cjsrch. The biggest challenges I have had, and are continuing to have, is skimming. I'm almost oblivious to the science behind it. But I'm trying, and I'm not stocking at all quite yet.(Corals) Don't get me wrong, I have living things, but they are hardy and few.
Temp may fluctuate a bit faster, as well as some other parameters but 24 gal isnt that small either.
I have had many small tanks over the years and found that they always did fine, and were just as stable. Just remember altough things in a small tank can slip faster they are easier to fix. A P04 problem for instance can be fixed with out a problem in a small tank but in a larger tank where larger water changes would be required it takes more.