There are others out there with the same warranty and service, with similar price points. My ProVari simply cannot fire my rda's or RBA's as the chip limits them too much. They are good for those that just want a simple tank or high ohm'd coil. I prefer any DNA20 build over their chip for flavor and vapor. My REO VV will also, and has the exact same service and warranty as ProVape offers. My all time favorite, out of the many I have tried and owned, including the elusive Caravela, will still be the seemingly simple, but well designed from a single block of aircraft aluminum, REO Grand.
It is simply a matter of personal preference, based on personal experience with many different kinds of PV's. You may be just fine with a ProVari and not need something that can give you the flavor and vapor I love so much from dripping (without dripping). I just fell in love with fresh juice on a coil and can't go back, much to the dismay of my poor ProVari, Vamo, Zmax and Caravela
But any of these I mention are not initially inexpensive, nor are they cheap (well the Vamo and Zmax are, as you stated, cheap and not repairable so thus expensive*). What they are is something you buy once and use daily without worrying about dropping and damaging and that is what to me makes them worth every penny spent, thus inexpensive in the long run.
ETA: * unless you are Bunnykiller with talent to revamp them!
There are lots of options. MY Zmax has a 4 amp limit. The Provari 3.5A cutoff will still take a 1.2 ohm coil to 3.7v and 11.5 watts. I vape 1.8 and 2 ohm coils and find them to be tasty with voluminous clouds at 3.4v when new and to 3.7V once they break in a bit.
You are right, they won't do sub ohm vaping.