When you consider what a variable voltage batt is used for - finding the 'sweet spot' for a flavor plus vapor - then I think the criticism of seeing the exact voltage marks is overrated - looking from the bottom of a Joye eGo-c Twist, you dial clockwise to increase voltage and dial counter-clockwise to reduce voltage.
If you're sampling, then you'l be dialing up or down a lot. But if you have an 'all day vape'/favorite flavor, then the dial is going to stay at the point you find best gets you the flavor and vapor that you want. Many with 'VV batts' never change the dial after they find what they need.
The true Joye eGo-C Twist has been the most durable and has the best short and charge protection on the market. The knock offs eGo VV can vary from DOA to 'I've been really lucky with ....'

You get what you pay for. I have mostly Joye eGo-c's and one Vision VV. The most notable difference for me is that the cutoff for the Joye eGo-c is about 13 seconds and the Vision (and this can vary from batt to batt) is about 6 to 7 seconds and with my vape style that interferes with my vaping. I haven't had any problems with the Vision except for that.
I've had Joye eGo-c's that lasted over a year. The only thing with the Joye eGo's is that they are susceptible to some really low resistance atomizers/coils. Anything less that 1.7 ohms can cause shorts. But with a VV batt that shouldn't be a problem since you can set the voltage to keep the wattage under 10-11 watts.
If you go with the Joye, then find a verified Joye vendor - cignot, heaven gifts, rocky mountain vapors, litecig, liberty flights, ecigbestsave, myvaporstore, sun vapors and others....