I just purchased a few licenses of litespeed 4-core and thought I'd share what we found.
9 apache servers serving 80% php files, 20% static (mysql is remote)
server load 0.9
3 litespeed servers serving 80% php files, 20% static (mysql is remote)
server load 0.5
66% less servers and still a 50% server load cut!
Exact same server specs but a HUGE performance increase. We bought 3 licenses but as a result were able to discontinue 6 servers!! Not to mention we could comfortable server everything from 2 servers or even 1 but we're keeping 3 as a fail over solution.
Great improvement and a great product, I cannot tell you how much I strongly recommend this product!