I did a lot of hiring in my day, sometimes having to sift through daunting stacks of resumes and cover letters. I definitely endorse what you said about personalizing. A resume and cover letter laser focused on the position is much more likely to get pulled from the stack than generic ones.

After you've looked at your 50th resume, things start to blur together.

Of course, there's a line between personalizing / being enthusiastic and being over the top. But I think all in all, it's better to flirt with that line than stay in the stack.