a simple potty does the job

This is a nice little potty that has served us well.

It is 2 pieces of plastic-- one piece is a chair with a hole in it for the bowl, complete with a back, armrests, and a bear on the back, and the other piece is the bowl, with an attached deflector. The bowl can be easily removed to dump the contents in the toilet (my daughter likes to do this herself- using the deflector as a handle), and is small enough it can be cleaned in the bathroom sink.

My daughter can easily carry the whole potty around the house. She likes the bear on it, too. This potty is just a potty-- it doesn't make any noise, or serve as a step stool. IMHO this is an advantage, because there's nothing to distract my child from the task at hand. It is very stable, and doesn't slip around on the floor when she's using it, or when she's getting up or down.

My only criticism is that my daughter doesn't need the deflector (and was a little worried about sitting on it), and even though we managed to use the potty with the bowl turned around so that the deflector was in the back, apparently the bowl is not symmetrical, as it doesn't fit perfectly that way. But it does fit well enough to be usable. It was also the most expensive option when I bought it-- funny how simplicity costs more!