Which one should I get? What’s the difference?
First the most obvious, Aspen screen size, the direct access buttons, knobs. The Aspen E5 is a NON TSO product based on the EFD Series TSO platform while the G5 started out as an “experimental” and now approved for certified aircraft.
The Aspen is capable of interfacing with older avionics utilizing composite signals and in a simpler installation using modern avionics and without an autopilot you don’t need any extra boxes. The G5 is a dual unit system, so the benefit is that even if one display goes black you still have ALL functions left in the other. You will need and external box that translates NAV signals to CAN bus signals that the G5 can understand.
G5 is plastic fantastic vs the Aspen aluminium casing but the G5 CAN bus makes the Garmin G5 versatile – 2 wire system interface with compatible equipment like the Garmin GFC500 autopilot. G5 and OAT will require a separate GAD29 OAT interface while the Aspen Avionics has both OAT and backup GPS built in the remote sensor module. Aspen has a better “user experience” and SVT synthetic vision… so the answer which one to go for?