Thanks for the reply, however, one would assume any decent software developer would perform these tests upfront (during design...) So, the short answer to your question is yes, WE have performed all these tests (including many more listed here). We've ported our system in other platforms and response time is 5x more.
Though, one thing we've notice, the slowness is more noticed only on sites that are password protected using the PA option offered in the Web tab. Slowness is Server related, not App related. This happens even on a single/simple html page. Server takes a long time before even sending request to the app.
As far as Big O... OH my... it's like asking a human if he knows how to walk.