Time: 100 years from now and energy weapons have been perfected.

Location: gun show for lethal energy weapons for home defense

My problem is:

I have two types of energy weapons one has a removable energy cartridge/ammo that you can charge separately.

The other energy gun was designed with a non-removable cartridge/ammo for convenience (can also be charged)

• Both are safe when handled by trained shooters.
• Both are safe from overcharging.
• Both designs are stable for long storage.
• Both designs have safety switches to prevent accidental firing.
• Both designs have the same shot count 15 shots
• Both designs charge to full in 15 minutes
• Both designs have trigger guards
• Both designs are priced the same

The only difference is the removable cartridge/ammo design.

The removable cartridge design allows you to buy 2 or more cartridges, and no residual charge inside the gun once cartridge is removed (gun is not loaded once cartridge is removed).

The non-removable cartridge means you are always loaded and ready.

Which will be the biggest seller? Will more people prefer the conventional removable cartridge/ammo design or will they prefer the non-removable cartridge/ammo design?