I only have the Provari, so I'll answer what I can on it.
Price:
Provari - $159, bare bones with 1 yr warranty, option for 1 yr additional
Lava Tube - depends on the manufacturer and distributor as there are a few knockoffs of this.
Weight:
Provari - 4 oz according to PBsuardo's review
Lava Tube - ?
How it Works:
ProVari - uses AccuSet™ technology; PWM (pulse-width modulation) boost circuit that uses a built-in dynamic self-calibration algorithm micropressor that keeps the output voltage accurate to 1% or better over the life of the product. The ProVari will constantly monitor and adjust itself to ensure you always get accurate voltage settings. In effect, what you set, you get, from the start of a battery to the end.
Uses a single button to fire the
device and work the menu system (5 clicks). Took me 10 minutes of playing with the menu to master it. Power up, power down, battery check, ohm check. Button begins blinking when battery needs replaced soon.
Lava Tube - ?
Three buttons.
How long will it last:
Provari - Because of the build and materials used, and the fact that Provape will service the Provari after warranty, I expect mine to last years.
Lava Tube - can't say, but the build and materials used in the LT are no comparison to the Provari's. Additionally, customer support for the LT is limited by the warranty from the vendor. After warranty expiration, I don't believe a broken LT will be repaired, only replaced by the owner. Consider this a disposable
device. I'll say the LT will likely last months.
Anything else?
With the Provari, you will get a time-tested APV known to be the standard in its class since it arrived. Every new APV gets compared to the Provari, and they all fail in some category. Provape has historically shown to update the Provari when the need arose for a minimal fee. Customer service is excellent. You actually get what you pay for, IMHO.
There is certainly a place for the Lava Tube. It's easier to justify its cheaper cost as long as you know what you are and are not getting with one. It is a satisfactory inexpensive variable voltage APV. I just wish they made them better to last and had better customer service.