Mark, this post on IP Readers vs Control Panels might be useful to you.
Personally in any greenfield deployment, networked AC should be much easier and quicker to deploy than centralized panels. Also any sites with existing network infrastructure and no current AC panels should be easier/cheaper.
Also many of the IP networked systems can drive a 12/24V strike using the PoE power to the controller; but you will still need standalone power supplies for mags/ELR solutions
As a rule I typically recomend networked devices for internal applications and traditional access control for external. When takin a "layered" security approach this is the best method IMO. Keep in mind one of the primary objectives of EAC is increasing delay to forced entry. By usining tradional devices externally you Increase delay time with the ability to use stronger locking devices. Internally you can add additional accountability at a much lower cost using network devices.