The dani extreme is not a 40w, it's a 20w device. The Dani extreme V2(and v2+) are the 40w devices.
The Provari mini 2.5 is not a VW but a VV device with a limit of 3.5A.
I only own the Dani extreme (not the Provari), and they are very reliable and beautifull devices, they have a bit more options than the Provari but not much. It is also a bit smaller than the Provari.
They both are older devices.
If you however get the Dani V2+ it's an whole other game, it has options galore. 40W, TC, manual TCR, powerboost, heat protection etc. etc. I own a few and they are very nice, it is expensive thoguh, roughly at the same price point as the Provari P3.
The Provari P3 is a VW device as opposed to the 2.5, but has only 20w, it has no temp control etc.
So if you go for one of the older devices, than it's mostly about looks and size, the Dicodes is a little more powerful though.
For the newer devices I would say the Dicodes wins hands down, it has far more features and power than the P3, also has better warranty.
I myself prefer the looks of the Dicodes, it's stylish and clean, but that's very personal
