Alternative of Networkwide Search plugins


I am using Ajax Search Pro in my multisite network for network wide search. However, it has gone substantially slow as the amount of data increased. now it takes more than a minute to get results. Beyond that it works great in every aspect - support of hundreds of themes, user search, custom fields, custom post types, priority search etc.

I tried Global Site search but it lacks most of the features mentioned above.

Is there any other advanced plugin that helps in Networkwide search?