The primary difference is the LYNX Touch L5100 has the ability to work as a Z-Wave controller; the L5000 does not.
The L5000 was the first self-contained, wireless touchscreen control panel to hit the market. It can achieve dual-path communication because it's compatible with internet communicators, like the ILP5, and cellular communicators, like the GSMVLP5. The L5100 has all these features, and it can work as a Z-Wave controller once the L5100 Z-Wave Module is installed. This gives users remote control of Z-Wave locks, lights, and thermostats. Another difference between the two control panels is the L5100 can support wireless internet connection through the use of the L5100-WiFi internet communicator. Because of these upgrades, the L5100 tends to be the system of choice for users.