Different PVs and what you might consider- Realize battery info: 100 mah= 1 hour
normal vaping before requiring recharge. If vaping on a variable volt at a higher voltage battery life will be diminished.
eGo Class:
JoyTech eGo fires @ 3.3 volts, SmokTech eGo fires @ 3.7 volts and the Kgo fires @ 3.7 volts- comes in 650, 900 or 1100 mah depending on the manufacturer- most popular 510 threading/ connection and are manual. I own a Kgo and I LOVE it. Have used the eGo and prefer the Kgo because of the higher voltage.
eGo Starter Kit cost anywhere from $50- $80.
Kgo starter kit costs about $40-$50:
KGO kit1100mAh by SLB original version
or
KGO kit1100mAh by SLB newer version
Mini Variable Volt PV: 510 threading/ connection. Manual Batteries.
Kgo VV- only comes in 650 mah- I own it and find battery life a problem.
Twist comes in 650, 900 and 1000 mah. Dial very narrow/ smooth and not easy to turn. Voltage numbers very hard to read/ invisible. Button occasionally sticks.
Vision Spinner comes in 400, 650, 900, 1100 and 1300 mah. Wide knurled voltage dial easy to turn and easy to read voltage markings. 1300 mah Spinner is the same size as 1000 Twist.
Both variable voltage PVs above fire from 3.3-4.8 volts.
I own both the Twists and Spinners and prefer the latter.
1300 Vision Spinner- 113mm or ~4.4 inches long; 16MM WIDE, 2MM WIDER THAN A STANDARD EGO
1100 Vision Spinner- 119mm or ~4.75 inches long
1000 Twist- Length 120mm(4.75")/Diameter 14mm
Advantage of the VV- when stressed and need a stronger hit I can easily and quickly dial up the voltage. For an all day vape I can lower it to 3.7-4.0. Also some flavors really shine at high voltage while others at a lower voltage.
My recommendation: If looking for a non VV the kgo is an excellent choice, has been out for well over a year and has many happy users.
If wanting a Mini VV the Spinner gets my

because of the size, ease of use and more powerful battery. Regardless of your choice any of the above mentioned PVs will give you a far superior vape and vapor. Also avoid ANY Starter Kit that comes with the outdated "tank" system- atomizers+ cartridges- prone to leaks and a waste of $$.