I agree with SM the herpstats have over and under temp protection, that the VE does not the mechanical relay is far more likely to fail off than on. Soft heat from cold. As far as I can see the VE has no safety features at all, it is just a plain thermostat. The biggest selling point is Rich.
Of the 4 reptile proportional units the VE is the skinniest on features. The herpkeeper has the one of the best communication features and alarm systems. The ecozone also has amazing alarm and monitoring features as well as the easiest to set. The herpstat has the most advanced safety systems and the ve and helix the most basic.