Some cool features of the enterprise:
The ability to view the last 3 boots and crash screens frame by frame as soon as POST Begins
The ability to control the System using a Java/Active X based iKVM Agent.
The ability to mount virtual media and boot to it (Eg an .iso or you can mount your local dvd drive.)
A dedicated management NIC if you choose to use it.
Cool things in general
The ability to deploy operating systems without needing driver disks (persistent storage of common drivers on a meser (embedded flash on mobo)
The ability to update drivers and firmware and roll back them using the Life Cycle Controller
The ability to control system power states and monitor consumption/usage.
I would go for the Enterprise unless you needed to VFlash to run an Embedded Hyper visor or OS. - FYI - You can boot to VFLASH
What server are your looking at?
Servers which include only a BMC in the base configuration.
PE R210, PE R310, PE R410, PE R510
PE T110, PE T310, PE T410
Servers which include idrac express regardless of configuration.
PE T610, and PE T710
See Table 1-1 for a Feature comparison