A variable power battery will allow you to adjust its output to improve the flavor and amount of vapor. Not all flavors taste their best at a fixed voltage, like your current battery. Some taste better with more heat to the coil, some taste best with less heat applied to the coil. It's also a matter of your personal preferences.
The Joytech Twist and Vision Spinner are popular eGo style batteries with variable power. There are also more advanced units called "mods" or advanced personal vaporizers (APV's) with even more power and other advanced features, like the Eleaf iStick or Innokin MVP.
The better the juice delivery device ( and usually the more expensive) the better the flavor and the more dense the vapor will be. I'm assuming that you are using a simple beginner's clearomizer, which may even be disposable. There are more advanced clearomizers, and other types of juice attachments which will provide better flavor and vapor results.
What you currently have is probably not a "bad" starter kit. At least you've gotten your foot in the door by starting to vape instead of smoking, and that's always a good thing. Whatever it takes to keep you off of the smokes.