I use a 510. my first useless e-cig (from before I found the forum) was about the same size a an analogue, but once I got the 510 I realised that the
vaping effect is such a different experience that you cannot compare the two. The vapour production becomes far more important than trying to look like a real cig.
The 510 is available in white if cosmetics are important, but the smaller it is, the less liquid it will hold (so you will be constantly refilling) and the shorter the battery life. I have asked my supplier to get me a mega battery (longer than the normal) to increase this, and when I get time I am considering making a
mod that will look nothing like a cig.... Vapour is the prime motivator. I only say this so that once you start, you will not waste money on what you think you want now, only to find a couple of weeks later that you want something different. My suggestion, go with a 510