Could be a coincidence but after working at a place that used a lot of them I've seen more trouble with Ranco's and Titanium heaters than with Jagers and Visitherms combined.
FWIW I use all Visitherm - for the last few years I've had them on a Reefkeeper.
FWIW I use all Visitherm - for the last few years I've had them on a Reefkeeper.