No mold/mildew issues.
I run them with dual stage Rancos and Ferm Wraps, so any temp between 38-100 is completely doable. I lager in one of my two freezers in kegs. Much easier and frees up space in the wine coolers.
I really don't understand the doggin on wine coolers. If they didn't work (and work extremely well), I wouldn't have 3 of them.