IMO i think the herpstat pro is not worth the money. I have 4 regular herpstats and everything runs smooth. Hatchrite is just moistened perlite. i'm a gecko breeder and there is no reason that i can't do the math on my own for water/perlite ratio. for our eggs we use a 1/.8 perlite/water by weight ratio. I don't know how humid snake eggs need to be though.
I run 4 racks. If my herpstat fails that's only 1 rack goes down. it's a matter of safety for the animals. I have not heard any bad things about ther herpstat pro but i try to reduce the risk.
I've got a Herp Pro and love it! I may be completely wrong, but isn't the USB package for the add on feature of calling your phone if temps go crazy?? I don't remember...
Each output of the Herpstat Pro is individually fused so if you had a short or something that overloaded an output it would only affect that one output. If you have a voltage spike or something unusualy like that and it takes out the processors then yes it would affect all four but if you have all four Herpstats hooked up a lightning strike can take all four of those out too. All the Herpstats are pretty darn tough though. It really comes down to everyones own comfort level. When you travel 70 mph down the highway most of us don't think about that $20 tierod end that connects our steering to the wheels. There are odds with anything.
The usb cable/software allows you to view your temps online and it will send you emails or text messages with the temps. It will also send emergency email/texts if something goes wrong (probe failure, computer loses connection with thermostat, ect). Its just a neat feature that some people like when they travel alot (can remotely check in) or just want an extra peace of mind. Like above though, if the computer crashes or the internet connection is unavailable you wont get the messages. You can only have so many backups for the backup.