Although I've never had much trouble with glass Visitherms or Ebos, I prefer not relying on the built-in thermostats too. I like titanium heaters, but I don't trust most of the commonly available ones. I'm currently using a bare Finnex titanium (no thermostat) on a Ranco controller which is working well.
I had a Won titanium, but the temp controller died after less than a year of use (stopped making heat). I cut the controller off and wired the element directly to a plug - works fine on the Ranco.