I like all that I've heard about this slideshow and it looks really great, but I want to verify that the image sizes can be changed up?
If the size of the slider is adjustable this looks like it could be amazing.
Also, is the description that comes over the the main image optional, or will that fall no matter what?

Thanks!

You can set a width dimension through the slide's category parameter for you images.
The size of the slideshow is customizable, as well as the whole slideshow itself.
The description is also optional among other things.

You can take a look here: www.joomlaworks.net/extensions/commercial-premium/frontpage-slideshow for a more detailed description of the product.