I haven't looked into VV devices as I was concerned about becoming accustomed to very high voltage. What would you recommend that would be similar in profile to the ego? Is it possible to apply too much voltage at which point you would no longer be vaping but smoking?
I wouldn't worry so much about being accustomed to high voltage. Actually, the voltage is but one element of achieving vaping zen. Depending on the resistance rating of whatever you're using i.e. cartomizer, atomizer, tank, etc, the voltage is what will drive it, yes, but if you're using a higher resistance carto et al, the over all
power will be at a 'comfortable level'.
Let me just put those words into an easier example:
Let's say right now you're using an eGo style battery, (which typical runs at ~3.3-3.4volts), with a 2.0ohm resisted cartomizer. Using Ohm's law, the overall
power you're using is around 5.7watts.
The equation is as followed: Voltage x Voltage / Resistance = Power, or, 3.4v x 3.4v / 2.0ohms = 5.7watts
Okay, so now let's say that you LOVE the way 5.7watts tastes but uh oh! You no longer have any 2.0ohm resisted cartos et al. Now what? Variable Voltage, my friend, is the answer. Let us say that instead of a 2.0ohm carto you now have a 3.0ohm carto, well all you would have to do is adjust the voltage (in this case, higher) to equate to what you're used to and what you love.
Now, without using all of the math, (which honestly, isn't even necessary), with any device, including VV, it's all about what tastes and feels good to you... not some number. So, if you decided to try VV on your eGo, you can grab a product called the eGo booster, which turns your eGo into a VV device, for a relatively decent price. (I will not post the link in this thread without Ben's permission, since this product is from another store). However, just search eGo booster in the search box and you should have no trouble finding it (or just google it).
As for the other inquiry, no, you cannot apply too much voltage to the point where you're actually smoking e-liquid. I mean, yes, there is always a way to reach that temperature, but, it's highly unlikely. In fact, I think it's dangerous to reach those levels of heat with PG/VG? (Not 100% sure on this?)
But you've no worries of that nature. Unless you're using a home-made carto et al (with a low enough resistance), most, if not all, devices won't let you reach a high enough level of voltage to achieve the said temperatures.
Sorry for the long post, I hope any of this will aid you.