Okay, here's the crash couse (no pun intended) on the modes of operations of GPWS and eGPWS. When I know of the differences, I'll try to differentiate between the 2 systems. Here are the modes, and the aural alerts that each creates (first line is initial warning, if things continue to deteriorate, the system steps up into a 2nd level):
1) Excessive descent rate
"Sink rate"
"Sink rate, whoop whoop pull up"
2) Excessive terrain closure rate (based on radio altitude)
"Terrain terrain"
"Terrain terrain, whoop whoop pull up"
3) Altitude loss after takeoff
"Don't sink"
4) Unsafe terrain clearance
4a (gear not in landing configuration)
"Too low terrain"
"Too low gear"
4b (flaps not in landing configuration)
"Too low terrain"
"Too low flaps"
5) Descent below glideslope
"glideslope" (half volume)
"GLIDESLOPE" (full volume)
6) Callouts
"Minimums minimums"
"50" "40" "30" "20" "10"
"Bank Angle"
7) Windshear detection and recovery
amber <WINDSHEAR> on PFD, stall protection pitch limit indicators and option to go around with escape pitch vectors, no audio
red <WINDSHEAR> on PFD, aural "<siren> WINDSHEAR WINDSHEAR WINDSHEAR", flight provides escape pitch vectors, stall protection pitch limit indicators
eGPWS enhances (hence the "e") mode 2 terrain warnings with a database of all terrain and obstacles (buildings, towers, bridges, antennae, etc) to build a map on the MFD. Added audio callouts are "Caution obstacle" "Caution terrain" and "Obstacle obstacle whoop whoop pull up" along with the capability of the MFP to snap to a terrain map at 10 mile scale if terrain or obstacles are in the flight path (30 secs to impact)