LiteSpeed is a great solution, and C-Servers strives to give our customers the best web server solutions.
Previously, we used a already mass-used solution based in Nginx as a web engine, and Memcached. While this solution was very efficient, some customers had trouble with Wordpress's .htaccess management, and Nginx showed some performance questions when serving dynamic content, on which Apache (from where Litespeed is based) is undoubtedly better.
With this new implementation of our Simply Unlimited, Everything Managed and Reseller web hosting solutions, we give a optimized paired solution, widely considered at least equivalent to LiteSpeed, in some instances even considered superior (when serving static content).
This solution consists of Varnish, Nginx and Apache together with PHP-FPM, with the correspondent proxying and caching of requests considering which type of content is being delivered at the moment, and with the correspondent optimizations in-place for those engines. It was already widely considered an optimized Nginx+Apache was close to LiteSpeed; with Varnish cache and PHP-FPM in place, it's also considered even better than Litespeed - simply requires more work from the provider, which C-Servers has put into place.
This is why we advertise our web server area as "LiteSpeed-Equivalent" - because it really is.