No intentional commercial plug, just a nice chart

. Here is an attempt to duplicate it, but not as good as the original.
Machine 429G Traveler 420S Aura "Everest" RemStar Pro 2 C-Flex RemStar Pro C-Flex
Manufact Puritan Bennett Puritan Bennett Aeiomed Respironics Respironics
110 Volt Yes Yes Yes Yes Yes
120 Volt Yes Yes Yes Yes Yes
DC Cable Yes Yes Yes Yes Yes
Direct Battery Yes Yes Yes Yes Yes
Integrated Bat No No Optional No No
Auto Altitude Yes Yes Yes Yes Yes
Ramp Yes Yes Yes Yes Yes
Hour/Session Yes Yes Yes Yes Yes
Opt Software No Yes No Yes Yes
Leak Compen Yes Yes Yes Yes Yes
Humidifier Yes Yes Yes Yes Yes
Passover Yes Yes Yes Yes Yes
Weight 1.75 1.75 2.2 3.9 3.9
Data Card No No No Yes Yes
Auto On/Off No No Yes Yes Yes
Warranty 2 yrs 2 yrs 2 yrs 2 yrs 2 yrs
Machine RemStar+ C-Flex RemStar Lite S8 Elite S8 Escape S8 Compact S7Elite
Manufact Respironics Respironics Resmed Resmed Resmed Resmed
110 Volt Yes Yes Yes Yes Yes Yes
220 Volt Yes Yes Yes Yes Yes Yes
DC Cable Yes Yes Yes Yes Yes No
Direct Battery Yes No No No No No
Integrated Bat No No No No No No
Auto Altitude Manual Manual Yes Manual Manual Yes
Ramp Yes Yes Yes Yes Yes Yes
Hour/Session Yes Yes Yes Yes Yes Yes
Opt Software No No Yes Yes No Yes
Leak Compen No No Yes No No No
Humidifier Yes Yes Yes Yes Yes Yes
Passover Yes Yes Yes Yes Yes Yes
Weight 3.9 3.9 2.9 2.9 2.9 5.07
Data Card No No Yes Yes No No
Auto On/Off No No Yes Yes No Yes
Warranty 2 yrs 2 yrs 2 yrs 2 yrs 2 yrs 2 yrs
Machine S7 Lightweight HC604 w/Heated Hose HC234 HC221LE HC220LE Trend 110
Manufact Resmed Fisher & Paykel Fisher & Paykel Fisher & Paykel Fisher & Paykel SomnoTech
110 Volt Yes Yes Yes Yes Yes Yes
220 Volt Yes Yes Yes Yes Yes Yes
DC Cable No No No No No No
Direct Battery No No No No No DC Inverter
Integrated Bat No No No No No No
Auto Altitude Manual Yes Manual Manual Manual Yes
Ramp Yes Yes Yes Yes Yes Yes
Hour/Session Yes Yes Yes Yes Yes Yes
Opt Software No Yes No Yes No No
Leak Compen No Yes Yes No No Yes
Humidifier Yes Yes Yes Yes Yes Yes
Passover Yes No No Yes Yes No
Weight 4.1 4.6 4.4 5 5
Data Card No No No No No No
Auto On/Off No Yes No No No Yes
Warranty 2 yrs 2 yrs 2 yrs 2 yrs 2 yrs 2 yrs