Hey, I've found long tapers feel more comfortable to be tattooed with and require less force to put in, You will definitely get better colour saturation with a 9mag as opposed to a seven, Curved magnums give you a softer look and are easier to blend with than flat mags (in my opinion). The voltage you run your NeoTat at will depend on how the skin is reacting to the colouring, start off low and turn it up until it puts it in the way you need for that particular application, Running the mag on the bottom of the bar ensures that the needle rides as flush as it can with the tube........