Are there any reasons not to use a default page in a link?

For example, my home page may be index.htm, and that is the default page. So, is there any benefit to having the link as domain.com/index.htm as opposed to just domain.com?

I have my links set up to reference only the domain name (without the default page in the link), and I think that is pretty common. However, here is the reason I ask:

I recently changed the names of some default pages. I updated the default page name on the webserver, so everything works like it always did. Only the underlying page name has changed. During the deep crawl I just had, I did not see any of the newly renamed default pages being spidered.

Does anyone know if Google actually caches the name of the default page, or if they just use the link only, and take whatever default page the webserver serves up?

I hope this makes sense.