I've had the notcigs original Infinity since feb, Buzz pro since they came out this summer.
Others have said it well. Buzz pro and the companion Infinity pro, are both really solid, true regulated output.
Bp and ip can both go to 15watts, drive 1.5 ohm dual coil to 4.7v, higher power than the other popular vv. I get consistent 6 - 7 ml of vaping between battery changes, at 5v, 8w, all day use; I believe you need extender cap and the big battery to get that on the provari, from numerous posts by provari owners.
By the time they are fully kitted, couple sets of batts, charger, extender for the provari, I believe bp comes in noticeably less costly, and the ip is actually another $30 less than the bp.
For notcigs, use the standard "ECF Buzzkill" coupon code (2 words).
Buzz service is top notch.
Provari also has many fans, undoubtedly a solid pv, just depends on if you are more into the high tech display vs. the bp/ip elegance.