IMO rain measurement is the Achilles heal of the WF smart weather (original model) system. Between .25 and .75 inches, my collocated Acurite 5/1, Stratus gauge, and WF smart will often show almost identical readings for rain. In other scenarios, the WF is not dependable.
Rain measurement was also the prime complaint of posters on the WF forum IIRC. The Tempest model, when first described there by WF employees, had lots of enticing, very generous warranty and satisfaction guarantees (they don't mention these much in subsequent announcements or literature, AFAIK). I think there was a very long time frame for return for refund no questions asked. However my WF enthusiasm is sufficiently dampened that I'll wait to read lots of real life performance reports, here or in the WF forum, no matter what the warranty or purchase price discounts, before I would (ever) buy a Tempest.
I'm sure the WF folks are fine people. But it did bug me when they all but acknowledged that the haptic system is not accurate, and then kept everybody on alert for months, waiting for the promised magical software fix. That turned out to be the system that uses some kind of crowd source measures from nearby supposedly accurate sources, and that means that for accurate measuring rain at my location, the WF is of almost no use.
Weatherflow reps have even written in the forum that a mechanical rain measuring system is being entertained as a future option, which sounds to me like another way of saying that the issues with the haptic sensors are here to stay.
Here's what I do like: the AIR half of the system, for temp/RH and lightning works fine and was convenient to mount in a shady location. I was disappointed that WF integrated everything into one unit for the Tempest, since this means that the jury is still out on how accurate the Tempest temp reads will be over time. They claim to have built compensation into the software, so I have to wonder if this is not yet again some kind of crowd-sourced data, in which case I don't want one.
The WF mounting system is great for somebody like me who has very limited mounting locations. I'd wish that every manufacturer would make their station attachable to ready-made camera-mount hardware.