"Best" is subjective.
The different choices of baking pans will effect texture and baking time. The more surface area the more crust and the faster the baking time.
Recipes call for a bread pan simply because then it looks like bread and is easier to slice. As you noticed, it does require longer to bake.
Muffin pans are also very popular because of the convenient shape and faster baking time.
If you like the shape and texture of your bread in a baking dish then by all means keep using it. I won't criticize you for it.
These are the things that popped up in my mind at first glance:
Volume
How bigger the thing, how longer it will take to be fully baked. This is the reason why you find such a difference in the baking times for banana bread and banana muffins.
Surface Area
The volume can be the same (ground surface x height), but the surface exposed to the heat can differ. If something is flatter, the center is more rapidly reached. If you would bake your bread in a normal bread mold, it would take a longer time than if you would flatten out a bread on a baking sheet (but note that the volume is the same).
Oven temperature
Something very obvious. If it's hotter, it won't have to bake as long. However, don't play too much with this. I would advice to use the temperature a recipe has recommended. If you put it too hot, the outer parts can burn, when the inner parts would not be baked fully.
This question is related.
Vessel Material
Some materials conduct heat better than others. As a consequence, some things will be faster done in metal than in glass for example. (But I believe this has a less important role than the other factors I've mentioned. I can't say much about it, since I don't know a lot about it.)
Best Answer
Time is only a rough indication of whether any dish is "done", the biggest 'unknown factor' from your question is, "what temp are you baking at?".
I would suggest you use the following 3 tests to determine when your banana bread is done (regardless of whether you are using pyrex or metal):
Each condition should be met in order, so don't bother with the toothpick until you see the rich brown color, then once the toothpick is clean, check the internal temp.