I just tried installing this plugin on my multisite implementation and when trying to activate it my entire network became unaccessible due to Server 500 errors.
The error itself is due to the plugin writing to the .htaccess file without placing itself on the start of a new line.
he # BEGIN comment is placed on the last line which then causes this problem.
...
RewriteRule . /index.php [L]
</IfModule># BEGIN W3TC Browser Cache
<IfModule mod_deflate.c>
...
I've manually placed #BEGIN... on a new line and it restored access to my site.
Please can you advise why this happened as it seems to be a common issue when I googled your plugin and this error where I found the solution here:
http://biostall.com/internal-500-server-error-after-activating-w3-total-cache-wordpress-plugin