Just some more info for anyone interested:
Overview: L-3’s Next Generation Electronic Standby Instrument System — GENESIS ESI-500 — is one of the most advanced standby instruments designed specifically for Part 23 (Class I, II, and III) airplanes and Part 27 rotorcraft. The compact unit is scalable and comes standard with altitude, attitude, slip/skid, vertical speed (VS) and aircraft track (via ARINC 429 source). Options are available for the display of navigation information and Synthetic Vision (SynVis), including terrain and obstacles. Magnetic heading is an available option when coupled with the low cost and compact MAG-500 magnetometer. The ESI-500 is compatible with existing NAV radios and GPS hardware. An internal lithium-ion battery pack automatically powers the system without interruption upon loss of main input power.
Certification: The ESI-500 will be submitted for TSO Authorization at the end of July, 2015. L-3 anticipates having TSO Authorization by September 2015. A comprehensive AML-STC list will be available shortly thereafter.
List price for basic unit: $5535 (street [price should be around $4400)
The Sandia unit looks like it will be a great unit but it's already a year behind the expected delivery date and still not available, List $3595 street price about 3K.