There are probably settings you can play with to make it better, but generally speaking yes, picture quality is always better on a smaller set.
The "depending on the program" part of your statement is important, too. Bigger, nicer TV's will show more of a broadcast's flaws, so that things that were acceptable on a smaller TV are not so much on a bigger one.
On the plus side, you really notice the difference with better sources (i.e. HD-DVD, Blu-Ray or good broadcast HD) a lot more on a bigger set than you will on your smaller one.