I have both a Lavatube and a Provari (among other mods). I would vote Provari all day. My Lavatube broke after a month of use (the battery cap fell off and the threading on the battery cap is off center, thus I can't change the battery anymore). The build quality between the Lavatube and the Provari aren't even in the same league. It's like buying a cheap mod box from Madvapes vs a professionally made wooden model from Red Sky Mods - the madvapes will work well, but you may need to buy another one in a few weeks.
My Provari is my go-to PV, it is always consistent, solid as a rock, and I never worry about it leaving me stranded. It is perfection in my opinion.
In addition, Provari's support team is absolutely phenomenal! I had an cartomizer break off and the threading was stuck in the adapter, also some of the chrome on my unit was starting to fade away. I sent it in and they sent me a brand new Provari within 3 days! Amazing customer service! I didn't even buy the extended guarantee (although if you are purchasing one, I HIGHLY RECOMMEND IT).