Hi David,
The same Demo License is available for Unity 5.x so you are good to go :)
Here is the related Unity 5.x info;
A demonstration system uses one of two different license files:
•Default license file (available on the Cisco Unity server).
•Time-limited license file (must be ordered from Cisco).
Limits on a Cisco Unity Demonstration System
Depending on the type of license file you use-Default License File or Time-Limited License File-the Cisco Unity demonstration system will have the limits listed below.
Default License File
10 languages
2 RealSpeak text-to-speech (TTS) sessions
10 mailboxes for one of the following subscriber types:
-Unified Messaging (UM) subscribers
-Voice Messaging (VM) subscribers
10 Cisco Unity Inbox subscribers
2 voice ports
2 voice-recognition sessions
30-second limit for messages
The ability to integrate with any supported phone system
Time-Limited License File
The time-limited license enables either Unified Messaging (UM) or Voice Messaging (VM) with the following limitations:
UM feature package
-50 UM subscribers with 16 sessions
-2 RealSpeak text-to-speech (TTS) sessions
-2 languages
-AMIS
-16 voice ports
-2 voice-recognition sessions
VM feature package
-50 VM subscribers with 16 sessions
-2 RealSpeak text-to-speech (TTS) sessions
-2 languages
-25 Cisco Unity Inbox users
-16 voice ports
-2 voice-recognition sessions
The time-limited license includes the following additional limitations:
Time limit (after which Cisco Unity stops handling calls)
-60 days
-90 days
Only one license file on the Cisco Unity server is permitted
Non-renewable
Locked to the specific MAC address of the network interface card (NIC) on the Cisco Unity server
The ability to integrate with any supported phone system
From this good doc;
http://www.cisco.com/en/US/docs/voice_ip_comm/unity/5x/release/notes/501curelnotes.html#wp42815
Hope this helps!
Rob
