The system should adapt to your style of practice not the opposite. Using the system should enhance the patient interaction and not detract from it. Do not buy a system without working with it for at least a day. Preferably visit more than one site where it is installed and spend the day and see how well it works. Consult both staff as well as physicians to see the level of satisfaction.
Cost is probably the least important parameter.
If system A cost twice as much as system B but enables you to work more efficiently and reduce staff it may actually be much more financially advantageous. Developed out of Dr. Zuliani's experience with the installation and utilization of his group practice's EPR system over the past 10 years.