Site Performance

I've been anxious to fully implement ZohoCRM into my small business. It has most of the functionality needed, usually only available in high-priced systems. However, the page loads and other site functions are so terribly slow I don't know how I can ever rely on this software for ongoing use during the business day. Why is it so slow? Is there anything that can be done about it? If not, I'm forced to continue my CRM search, which I'm growing very weary of.
gregdbc