Since there is no cutoff on a manual battery you can inhale for as long as you want. The VX2 auto battery has about an 8 second cutoff, so if you can inhale longer than 8 seconds using the manual battery, then yes, you'll get more vapor.
Also, you'll be able to drip on the atty without worrying about destroying the battery. Dripping on the atty can increase vapor production as well.
Another advantage to a manual battery is that you don't have to worry about it activating accidentally on it's own from sound/vibration, etc.
