Is the asycronous ad loading script working properly?

[scott001]

I've noticed two things when I use the asyncjs.php script to load multiple banners per page on my site that make me question whether or not the async code is doing what it should be doing:

1) If I remove "async" from the script tag, so this: 
<script src="/adserv/www/delivery/asyncjs.php"></script>
instead of this:
<script async src="/adserv/www/delivery/asyncjs.php"></script>
I get faster page speed scores from Google. There is no comparison, at least 10% faster. Why?

2) Google penalizes me for not lazy loading my banner ads with async loading. I thought that if you load something async, everything else on the page will load without delay, and the async loaded content will load simultaneously and not slow anything down. The fact that I'm getting a 1.5 second penalty from Google about not lazy loading my ad banners tells me that perhaps the async script is not functioning as designed. 

Any help would be appreciated!