I have use and do have some v4l bats. They are handy once in a while but I much prefer my Ego Bats.
V4l is a good vender, the only problem is you never know what you are buying now.
they change designs and juice very frequently and so when purchasing you really dont know if you are getting the old design , or the new one , or the new new one etc.
Which has led to me no longer ordering from them.
some of their bats have a 13 sec cut off and some dont, some have a more airy draw and some dont, some of the cartos dont seem to fit some of their batteries, and some do,
Problem is , you dont know which is which when ordering.
The equipment they sell is good, no doubt about that, if you can figure out which is which and what it will work with without modding it when you get it new.
That pretty much sums up V4L. I had a few quality control issues when I used to order from them,but I won't go into that. Bottom line is... The Ego,Tornado,or Riva blow the KR808 away for the same price. V4L is way behind the curve right now.