There are fewer servers (three rather than five), so you may be running into conflicts that weren't there in the old environment. I've just downloaded it to check it out, and ELGG does a metric crapload of stuff while it's running (there are at least 48 PHP files loaded on an index.php request in version 1.8.8, along with a dizzying number of database queries if there are any users -- and that's not even beginning to consider plugins), so it may simply be the case that not all of the page-generation stuff is finished by the time your 30 seconds is up -- it all depends on what else is happening on the server at the time. Unfortunately, there are a lot of sites that could be simple static HTML or very lightweight blog engines running on WP, Drupal and Joomla, and all of them are resource-heavy as well (deeply nested include/require statements, dozens upon dozens of database hits that depend on previous database hits, etc.).
I don't want to sound like a shill -- I have no connection to x10 other than as a user, and have no financial stake in the matter at all -- but I have to say that paying for something on a less-stressed server (either Illuminated or Premium) might solve a lot of problems. Even when the nominal resources are the same (especially maximum execution time), the fact that you're not in competition with another few tens of thousands of SQL queries for a spot on the queue will make your app a lot more responsive.
