New nginx convert. Please comment on my config

I just migrated our drupal site to nginx from apache.

I based my config on perusio's setup using drupal_boost.conf.
We have a main site and then a couple subsites using drupal multisite configuration. I think I configure it correctly. But please let me know if I did anything wrong or any improvement I can make. The complete conf file is here http://pastebin.com/y22PV59f

I'm not sure about this part:

location / {
# This is cool because no php is touched for static content
try_files $uri @cache;
}

    location /sub1 {
            rewrite ^/([^/]*)/(.*)(/?)$ /$1/index.php?q=$2&$args;
            try_files $uri $uri/ @cache;
    }

    location /sub2 {
            rewrite ^/([^/]*)/(.*)(/?)$ /$1/index.php?q=$2&$args;
            try_files $uri $uri/ @cache;
    }

    location @drupal {
            rewrite ^ /index.php;
    }

Thanks.