Our IoT service uses the RPi2. We will move to the RPi3 when our stock runs out.
In our B2B application, the Pi's are just headless data collectors and all C code and data normally runs in RAM with the SSD card only written to as a backup if the device loses Internet connectivity (rare). The SSD card's system partition is configured as read only and we have had no problems with data corruption.
I think many people are trying to use these small computers for things that were not intended. The RPi's are cheap, well supported, and more than powerful enough for the price. If you need more power, spend more on some of the other options or step up to a full computer.