If you use Faces, you'll have to design pages so they won't use too much client side memory.
It's possible to create complext application but you'll need to design it "correctly" for liferay framework. Most developers having problems with liferay development are caused by improper application design. It's not the tool but how to use it properly. :-)

I just posted an answer to a similar question in a different thread.

Regarding performance of portlet/webapp frameowrks, there is often a tradeoff between performance and ease of development. The JSF framework offers lots of great features and conveniences to developers, but it requires a portlet bridge that causes the portlet lifecycle to invoke the JSF lifecycle. How many users will you have in your system that would concurrently work with a JSF portlet?

Thank you very much for your response Neil.
I am expecting between 50 and 100 users accessing the portlet concurrently.

Best regards,
Anand

Hi Anand,

Provided that there are no performance bottlenecks in your portlet, 50-100 concurrent users should be no problem at all.

Best Regards,

Neil

Thank you very much Neil.