Unfortunately, most of the testimony is not read, or at least the content of the testimony isn't. Usually the Chair sits there and flips over the pages of testimony and says something like "supports" or "opposes" the bill at hand. That being said, it does sometimes get read, so it is always better to write a little something just in case. But, as was previously mentioned, you can just hit the "support" or "oppose" button.
I will be trying to get some model testimony set up (for next year), so hopefully that will help.
Aloha