When I bought a VV
device I bought an IP. This is how I see it.
Price: Lavatube, by far
Reliability: IP, this can be easily be determined by reading what owners have to say in these forums.
Support: IP, these are produced and sold by active ECF members whom you can talk to here and who are very quick to take care of any problems. Small business vs large production facility far far away.
Digital vs Analog voltage control: this obviously is user preference, the dial on an IP is much simpler to use and the digital is more informative but totally unnecessary for
vaping experience. If you are the type of person who wants a CPU meter running on your PC or a tachometer in your auto transmission car you will probably like the digital controls. If you are occasionally curious about V with an IP you can always buy a cheap meter to check V at a particular setting.
Appearance: With IP you can get an attractive anodized metal finish with brass or chrome caps. Lavatube looks like most mass produced items, rather utilitarian, but not unsightly.
In the end they should both vape pretty much the same.