Model 1 works ok, not all that suited to heavy duty/thick pcbs, but it's fine for normal stuff.
I've seen them fail in a few ways though.
- The switches tend to be bad quality and need replacing.
- The one I had used each side of the DPST switch to do different things. One side started the fan and the other started the heater logic. Which meant when one side of the switch failed the fan stopped but the heater stayed on.
- Blower fan eventually gets really noisy and fails due to bearing quality not being that good