The Vegas and Axis ARE duplicate lines for floor plan and chassis.
The differences are in the front cap design, colors, and interior fabrics.
It is noteworthy that these RV's are built on a chassis that is NOT used by any other maker that I know of. It is a stripped Ford E-Series (not the F53 like all other gas Class A's). It has V10 power like the E450, and an independent front suspension vs. the I-Beam in the F53 for a much better ride.
The Chassis can tow as well as any Class C on the Ford E-Series cab chassis...8,000lb receiver is standard. Actual towable weight depends on how you load the RV (up to 22,000GCWR for all floor plans, except the smaller 24.1 at 18,000lb).
The AirCon is 1 roof unit and the dash air. Should work with no issues in 100degree heat.
The generator is a gas powered unit that pulls fuel from the main tank...very easy to use.
Service is exactly like a V10 pick-up...and inexpensive.
These RV's are VERY innovative and have few, if any competition (Winnie Via is close but Diesel powered and much more $$).
Pick the floor plan you like and take a test drive. I think you will like what you find.
Best luck